Change search
Refine search result
123 1 - 50 of 120
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abbas, Ghazanfar
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. COMSATS Institute of Information Technology, Pakistan.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. COMSATS Institute of Information Technology, Pakistan.
    Khan, M. Ajmal
    Ahmad, Imran
    Chaudhry, M. Ashraf
    Sherazi, Tauqir A.
    Mohsin, Munazza
    Ahmad, Mukhtar
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Synthesize and characterization of nanocomposite anodes for low temperature solid oxide fuel cell2015In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 40, no 1, p. 891-897Article in journal (Refereed)
    Abstract [en]

    Solid oxide fuel cells have much capability to become an economical alternative energy conversion technology having appropriate materials that can be operated at comparatively low temperature in the range of 400-600 degrees C. The nano-scale engineering has been incorporated to improve the catalytic activity of anode materials for solid oxide fuel cells. Nanostructured Al0.10NixZn0.90-xO oxides were prepared by solid state reaction, which were then mixed with the prepared Gadolinium doped Ceria GDC electrolyte. The crystal structure and surface morphology were characterized by XRD and SEM. The particle size was evaluated by XRD data and found in the range of 20-50 nm, which was then ensured by SEM pictures. The pellets of 13 mm diameter were pressed by dry press technique and electrical conductivities (DC and AC) were determined by four probe techniques and the values have been found to be 10.84 and 4.88 S/cm, respectively at hydrogen atmosphere in the temperature range of 300-600 degrees C. The Electrochemical Impedance Spectroscopy (EIS) analysis exhibits the pure electronic behavior at hydrogen atmosphere. The maximum power density of ANZ-GDC composite anode based solid oxide fuel cell has been achieved 705 mW/cm(2) at 550 degrees C.

  • 2. Adit Maark, T.
    et al.
    Hussain, T.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Structural, electronic and thermodynamic properties of Al- and Si-doped α-, γ-, and β-MgH2: Density functional and hybrid density functional calculations2012In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, no 11, p. 9112-9122Article in journal (Refereed)
    Abstract [en]

    In this work, we present a detailed study of Al- and Si-doped α-, γ-, and β-MgH 2 phases using the gradient corrected density functional GGA-PBE and the hybrid Hartree-Fock density functionals PBE0 and HSE06 within the framework of generalized Kohn-Sham density functional theory (DFT) using a plane-wave basis set. We investigate the structural, electronic, and thermodynamical properties of these compounds with regard to their hydrogen storage effectiveness. PBE0 and HSE06 predict cell parameters and bond lengths that are in good agreement with the GGA-PBE calculations and previously known experimental results. As expected smaller band gaps (E gs) are predicted by GGA-PBE for the pure magnesium hydride phases. PBE0 overcomes the deficiencies of DFT in treating these materials better than HSE06 and yields E gs that compare even better with previous GW calculations. Both the hybrid functionals increase the E gs of the Al-doped magnesium hydrides by much less magnitudes than of the Si-doped phases. This difference is interpreted in terms of charge density distributions. Best H 2 adsorption energies (ΔH ads) are computed by HSE06 while GGA-PBE significantly overestimates them. Si-doped α- and β-MgH 2 exhibited the least negative ΔH ads in close proximity to the H 2 binding energy range of -0.21 to -0.41 eV ideal for practical H 2 storage transportation applications.

  • 3.
    Afzal, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Madaan, Sushant
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Dong, Wenjing
    Raza, Rizwan
    Xia, Chen
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Hubei University, China.
    Analysis of a perovskite-ceria functional layer-based solid oxide fuel cell2017In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 27, p. 17536-17543Article in journal (Refereed)
    Abstract [en]

    A fuel cell based on a functional layer of perovskite Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) composited samarium doped ceria (SDC) has been developed. The device achieves a peak power density of 640.4 mW cm(-2) with an open circuit voltage (OCV) of 1.04 Vat 560 degrees C using hydrogen and air as the fuel and oxidant, respectively. A numerical model is applied to fit the experimental cell voltage. The kinetics of anodic and cathodic reactions are modeled based on the measurements obtained by electrochemical impedance spectroscopy (EIS). Modeling results are in well agreement with the experimental data. Mechanical stability of the cell is also examined by using analysis with field emission scanning electron microscope (FESEM) associated with energy dispersive spectroscopy (EDS) after testing the cell performance.

  • 4. Ahmad, Muhammad Ashfaq
    et al.
    Akram, Nadeem
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Structural and electrical characterisation of nanostructure electrodes for SOFCs2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 30, p. 17487-17491Article in journal (Refereed)
    Abstract [en]

    This paper reports the effects of sintering temperature on structure, particle size and conductivity of electrodes (Sn0.2Zn0.8Fe0.2O & Sn0.8Zn0.2Fe0.2O). The electrode material was prepared by the chemical method combining a solid state reaction. Structural analyses were performed using X-ray diffraction and scanning electron microscopy. The particle size of the material obtained using Scherrer's formula was 50-60 nm and the nanostructure's surface was studied using electrochemical characterisations tools. Electrical conductivity was determined using the 4-probe DC method, which was compared with the 4-probe AC method. These results suggest a promising substitute for the conventional electrodes of solid oxide fuel cells (SOFCs). It is known that a sintering temperature above 1000 degrees C causes an increase in density and a reduction of porosity. Therefore, we optimised the sintering temperature at 1000 degrees C and obtained electrical conductivity of about 5 S Thus, this electrode could play a vital role in the development of high performance SOFCs at intermediate temperatures.

  • 5. Ahmed, A.
    et al.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. COMSATS Institute of Information Technology, Pakistan.
    Khalid, M. S.
    Saleem, M.
    Alvi, F.
    Javed, M. S.
    Sherazi, T. A.
    Akhtar, M. N.
    Akram, N.
    Ahmad, M. A.
    Rafique, A.
    Iqbal, J.
    Ali, A.
    Ullah, M. K.
    Imran, S. K.
    Shakir, I.
    Khan, M. A.
    Zhu, B.
    Highly efficient composite electrolyte for natural gas fed fuel cell2016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 16, p. 6972-6979Article in journal (Refereed)
    Abstract [en]

    Solid oxide fuel cells (SOFCs) have the ability to operate with different variants of hydro carbon fuel such as biogas, natural gas, methane, ethane, syngas, methanol, ethanol, hydrogen and any other hydrogen rich gas. Utilization of these fuels in SOFC, especially the natural gas, would significantly reduce operating cost and would enhance the viability for commercialization of FC technology. In this paper, the performance of two indigenously manufactured nanocomposite electrolytes; barium and samarium doped ceria (BSDC-carbonate); and lanthanum and samarium doped ceria (co-precipitation method LSDC-carbonate) using natural gas as fuel is discussed. The nanocomposite electrolytes were synthesized using co-precipitation and wet chemical methods (here after referred to as nano electrolytes). The structure and morphology of the nano electrolytes were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fuel cell performance (OCV) was tested at temperature (300-600 °C). The ionic conductivity of the nano electrolytes were measured by two probe DC method. The detailed composition analysis of nano electrolytes was performed with the help of Raman Spectroscopy. Electrochemical study has shown an ionic conductivity of 0.16 Scm-1 at 600 °C for BSDC-carbonate in hydrogen atmosphere, which is higher than conventional electrolytes SDC and GDC under same conditions. In this article reasonably good ionic conductivity of BSDC-carbonate, at 600 °C, has also been achieved in air atmosphere which is comparatively greater than the conventional SDC and GDC electrolytes.

  • 6.
    Ajmal Khan, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Bohn Lima, Raquel
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Chaudhry, M. Asharf
    Ahmed, E.
    Abbas, Ghazanfar
    Comparative study of the nano-composite electrolytes based on samaria-doped ceria for low temperature solid oxide fuel cells (LT-SOFCs)2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 36, p. 16524-16531Article in journal (Refereed)
    Abstract [en]

    Ceria-based electrolyte materials have great potential in low and intermediate temperature solid oxide fuel cell applications. In the present study, three types of ceria-based nanocomposite electrolytes (LNK-SDC, LN-SDC and NK-SDC) were synthesized. One-step co-precipitation method was adopted and different techniques were applied to characterize the obtained ceria-based nano-composite electrolyte materials. TGA, XRD and SEM were used to analyze the thermal effect, crystal structure and morphology of the materials. Cubic fluorite structures have been observed in all composite electrolytes. Furthermore, the crystallite sizes of the LN-SDC, NK-SDC, LNK-SDC were calculated by Scherrer formula and found to be in the range 20 nm, 21 nm and 19 nm, respectively. These values emphasize a good agreement with the SEM results. The ionic conductivities were measured using EIS (Electrochemical Impedance Spectroscopy) with two-probe method and the activation energies were also calculated using Arrhenius plot. The maximum power density was achieved 484 mW/cm(2) of LNK-SDC electrolyte at 570 degrees C using the LiCuZnNi oxide electrodes.

  • 7.
    Alexiadis, Alessio
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Dudukovic, M P
    Ramachandran, P
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Wanngard, J
    Bokkers, A
    On the electrode boundary conditions in the simulation of two phase flow in electrochemical cells2011In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, no 14, p. 8557-8559Article in journal (Refereed)
  • 8.
    Ali, Amjad
    et al.
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan.;Univ Okara, Dept Phys, Okara 56300, Pakistan.;KTH, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden..
    Bashir, Farrukh Shehzad
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Raza, Rizwan
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan.;Royal Inst Technol KTH, Dept Energy Technol, S-10044 Stockholm, Sweden..
    Rafique, Asia
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Ullah, Muhammad Kaleem
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Alvi, Farah
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Afzal, Muhammad
    Royal Inst Technol KTH, Dept Energy Technol, S-10044 Stockholm, Sweden..
    Ghauri, Moinuddin
    COMSATS Univ Islamabad, Dept Chem Engn, Lahore Campus, Lahore 54000, Pakistan..
    Belova, Lyubov M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Electrochemical study of composite materials for coal-based direct carbon fuel cell2018In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 28, p. 12900-12908Article in journal (Refereed)
    Abstract [en]

    The efficient conversion of solid carbon fuels into energy by reducing the emission of harmful gases is important for clean environment. In this regards, direct carbon fuel cell (DCFC) is a system that converts solid carbon directly into electrical energy with high thermodynamic efficiency (100%), system efficiency of 80% and half emission of gases compared to conventional coal power plants. This can generate electricity from any carbonaceous fuel such as charcoal, carbon black, carbon fiber, graphite, lignite, bituminous coal and waste materials. In this paper, ternary carbonate-samarium doped ceria (LNK-SDC) electrolyte has been synthesized via co-precipitation technique, while LiNi-CuZnFeO (LNCZFO) electrode has been prepared using solid state reaction method. Due to significant ionic conductivity of electrolyte LNK-SDC, it is used in DCFC. Three types of solid carbon (lignite, bituminous, sub-bituminous) are used as fuel to generate power. The X-ray diffraction confirmed the cubic crystalline structure of samarium doped ceria, whereas XRD pattern of LNCZFO showed its composite structure. The proximate and ultimate coal analysis showed that fuel (carbon) with higher carbon content and lower ash content was promising fuel for DCFC. The measured ionic conductivity of LNK-SDC is 0.0998 Scm(-1) and electronic conductivity of LNCZFO is 10.1 Scm(-1) at 700 degrees C, respectively. A maximum power density of 58 mWcm(-2) is obtained using sub bituminous fuel.

  • 9.
    Ali, Amjad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Materials Technology.
    Shehzad Bashir, F.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Rafique, A.
    Kaleem Ullah, M.
    Alvi, F.
    Afzal, Muhammad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Ghauri, M.
    Belova, Lyubov
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Electrochemical study of composite materials for coal-based direct carbon fuel cell2018In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 28, p. 12900-12908Article in journal (Refereed)
    Abstract [en]

    The efficient conversion of solid carbon fuels into energy by reducing the emission of harmful gases is important for clean environment. In this regards, direct carbon fuel cell (DCFC) is a system that converts solid carbon directly into electrical energy with high thermodynamic efficiency (100%), system efficiency of 80% and half emission of gases compared to conventional coal power plants. This can generate electricity from any carbonaceous fuel such as charcoal, carbon black, carbon fiber, graphite, lignite, bituminous coal and waste materials. In this paper, ternary carbonate-samarium doped ceria (LNK-SDC) electrolyte has been synthesized via co-precipitation technique, while LiNiCuZnFeO (LNCZFO) electrode has been prepared using solid state reaction method. Due to significant ionic conductivity of electrolyte LNK-SDC, it is used in DCFC. Three types of solid carbon (lignite, bituminous, sub-bituminous) are used as fuel to generate power. The X-ray diffraction confirmed the cubic crystalline structure of samarium doped ceria, whereas XRD pattern of LNCZFO showed its composite structure. The proximate and ultimate coal analysis showed that fuel (carbon) with higher carbon content and lower ash content was promising fuel for DCFC. The measured ionic conductivity of LNK-SDC is 0.0998 Scm−1 and electronic conductivity of LNCZFO is 10.1 Scm−1 at 700 °C, respectively. A maximum power density of 58 mWcm−2 is obtained using sub-bituminous fuel.

  • 10.
    Andersson, Joakim
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Energy Processes.
    Grönkvist, Stefan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Energy Processes.
    Large-scale storage of hydrogen2019In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 44, no 23, p. 11901-11919Article in journal (Refereed)
    Abstract [en]

    The large-scale storage of hydrogen plays a fundamental role in a potential future hydrogen economy. Although the storage of gaseous hydrogen in salt caverns already is used on a full industrial scale, the approach is not applicable in all regions due to varying geological conditions. Therefore, other storage methods are necessary. In this article, options for the large-scale storage of hydrogen are reviewed and compared based on fundamental thermodynamic and engineering aspects. The application of certain storage technologies, such as liquid hydrogen, methanol, ammonia, and dibenzyltoluene, is found to be advantageous in terms of storage density, cost of storage, and safety. The variable costs for these high-density storage technologies are largely associated with a high electricity demand for the storage process or with a high heat demand for the hydrogen release process. If hydrogen is produced via electrolysis and stored during times of low electricity prices in an industrial setting, these variable costs may be tolerable.

  • 11. Basile, A.
    et al.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Iulianelli, A.
    Cigolotti, V.
    European Fuel Cell 20112013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 1, p. 319-319Article in journal (Other academic)
  • 12.
    Benamira, M.
    et al.
    Chimie ParisTech.
    Ringuede, A.
    Chimie ParisTech.
    Hildebrandt, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Vannier, R-N
    UMR 8181 CNRS.
    Cassir, M.
    Chimie ParisTech.
    Gadolinia-doped ceria mixed with alkali carbonates for SOFC applications: II - An electrochemical insight2012In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, no 24, p. 19371-19379Article in journal (Refereed)
    Abstract [en]

    Composite materials based on gadolinia-doped ceria (GDC) and alkali carbonates (Li2CO3-K2CO3 or Li2CO3-Na2CO3) are potential electrolytes for low temperature solid oxide fuel cell applications (LTSOFC). This paper completes a first one dedicated to the thermal, structural and morphological study of such compounds; it is fully focussed on their electrical/electrochemical properties in different conditions, temperature, composition and gaseous atmosphere (oxidative or reductive). The influence of the gaseous composition on the Arrhenius conductivity plots is evidenced, in particular under hydrogen atmosphere. Finally, electrical conductivity determined by impedance spectroscopy is presented as a function of time to highlight the stability of such composites over 6000 h. First results on single cells showed performance at 600 degrees C of 60 mW cm(-2).

  • 13.
    Björklund, Anna
    et al.
    KTH, Superseded Departments, Chemical Engineering and Technology.
    Melaina, Marc
    Keoleian, Gregory
    Hydrogen as a transportation fuel produced from thermal gasification of municipal solid waste: an examination of two integrated technologies2001In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 26, no 11, p. 1209-1221Article in journal (Refereed)
    Abstract [en]

    Innovative technologies are required to offset increasing consumption and declining stocks of non-renewable resources. This study examines a possible enhancement of waste management and transportation by integrating two emerging technologies: municipal solid waste (MSW) gasification and fuel cell vehicles (FCVs), by fueling FCVs with hydrogen produced from gasified MSW. Material and energy flows were modeled in four MSW management scenarios (incineration, landfill, gasification, gasification with recycling) and four transportation scenarios (hybrid gasoline-electric, methanol FCVs, hydrogen FCVs using hydrogen from natural gas or municipal solid waste). Technological performance deemed feasible within 2010–2020 was assumed. Greenhouse gas emissions and non-renewable energy use were used to assess overall system performance. Gasification with hydrogen production performs as efficiently as incineration, but is advantageous compared to landfilling. Taking into account additional environmental criteria, the model suggests that hydrogen from MSW gasification for FCVs may provide benefits over conventional MSW treatment and transportation systems.

  • 14. Callini, Elsa
    et al.
    Aguey-Zinsou, Kondo-Francois
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Uppsala Univ, Sweden.
    Ramon Ares, Jose
    Bals, Sara
    Biliskov, Nikola
    Chakraborty, Sudip
    Charalambopoulou, Georgia
    Chaudhary, Anna-Lisa
    Cuevas, Fermin
    Dam, Bernard
    de Jongh, Petra
    Dornheim, Martin
    Filinchuk, Yaroslav
    Novakovic, Jasmina Grbovic
    Hirscher, Michael
    Jensen, Torben R.
    Jensen, Peter Bjerre
    Novakovic, Nikola
    Lai, Qiwen
    Leardini, Fabrice
    Gattia, Daniele Mirabile
    Pasquini, Luca
    Steriotis, Theodore
    Turner, Stuart
    Vegge, Tejs
    Zuttel, Andreas
    Montone, Amelia
    Nanostructured materials for solid-state hydrogen storage: A review of the achievement of COST Action MP11032016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 32, p. 14404-14428Article in journal (Refereed)
    Abstract [en]

    In the framework of the European Cooperation in Science and Technology (COST) Action MP1103 Nanostructured Materials for Solid-State Hydrogen Storage were synthesized, characterized and modeled. This Action dealt with the state of the art of energy storage and set up a competitive and coordinated network capable to define new and unexplored ways for Solid State Hydrogen Storage by innovative and interdisciplinary research within the European Research Area. An important number of new compounds have been synthesized: metal hydrides, complex hydrides, metal halide ammines and amidoboranes. Tuning the structure from bulk to thin film, nanoparticles and nanoconfined composites improved the hydrogen sorption properties and opened the perspective to new technological applications. Direct imaging of the hydrogenation reactions and in situ measurements under operando conditions have been carried out in these studies. Computational screening methods allowed the prediction of suitable compounds for hydrogen storage and the modeling of the hydrogen sorption reactions on mono-, bi-, and three-dimensional systems. This manuscript presents a review of the main achievements of this Action.

  • 15. Cassir, Michel
    et al.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Basile, Angelo
    Strategic views on molten carbonates: An introduction to the special issue section on the "2015 International Workshop on Molten Carbonates & Related Topics (IWMC2015), 11-13 June, 2015, Shenyang, China"2016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 41, p. 18687-18691Article in journal (Refereed)
  • 16. Chanda, Debabrata
    et al.
    Dobrota, Ana S.
    Hnat, Jaromir
    Sofer, Zdenek
    Pašti, Igor
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Skorodumova, Natalia, V
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Paidar, Martin
    Bouzek, Karel
    Investigation of electrocatalytic activity on a N-doped reduced graphene oxide surface for the oxygen reduction reaction in an alkaline medium2018In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 27, p. 12129-12139Article in journal (Refereed)
    Abstract [en]

    Today the search for new energy resources is a crucial topic for materials science. The development of new effective catalysts for the oxygen reduction reaction can significantly improve the performance of fuel cells as well as electrocatalytic hydrogen production. This study presents the scalable synthesis of nitrogen-doped graphene oxide for the oxygen reduction reaction. The combination of an ab initio theoretical investigation of the oxygen reduction reaction (ORR) mechanism and detailed electrochemical characterization allowed the identification of electrocatalytically active nitrogen functionalities. The dominant effect on electrocatalytic activity is the presence of graphitic and pyridinic nitrogen and also N-oxide functionalities. The overpotential of ORR for nitrogen-doped graphene oxide prepared by microwave-assisted synthesis outperformed the metal-doped graphene materials.

  • 17. Chen, Mingming
    et al.
    Wang, Chengyang
    Niu, Xiaomeng
    Zhao, Shuo
    Tang, Jian
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Carbon anode in direct carbon fuel cell2010In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 35, no 7, p. 2732-2736Article in journal (Refereed)
    Abstract [en]

    Direct carbon fuel cell (DCFC) is a kind of high temperature fuel cell using carbon materials directly as anode. Electrochemical reactivity and surface property of carbon were taken into account in this paper. Four representative carbon samples were selected. The most suitable ratio of the ternary eutectic mixture Li2CO3-K2CO3-Al2O3 was determined at 1.05:1.2:1(mass ration). Conceptual analysis for electrochemical reactivity of carbon anode shows the importance of (1) reactive characteristics including lattice disorder, edge-carbon ratio and the number of short alkyl side chain of carbon material, which builds the prime foundation of the anodic half-cell reaction; (2) surface wetting ability, which assures the efficient contact of anode surface with electrolyte. It indicates that anode reaction rate and DCFC output can be notably improved if carbon are pre-dispersed into electrolyte before acting as anode, due to the straightway shift from cathode to anode for CO32- provided by electrolyte soaked in carbon material.

  • 18.
    Chen, Mingming
    et al.
    Tianjin Univ, Sch Chem Engn & Technol, China.
    Zhang, Hongjuan
    Fan, Liangdong
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Wang, Chengyang
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Hubei Univ, Fac Phys & Elect Sci, Hubei Collaborat Innovat Ctr Adv Organ Chem Mat, China.
    Ceria-carbonate composite for low temperature solid oxide fuel cell: Sintering aid and composite effect2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 23, p. 12309-12316Article in journal (Refereed)
    Abstract [en]

    In this study, the effect of carbonate content on microstructure, relative density, ionic conductivity and fuel cell performance of Ce0.8Sm0.2O1.9-(Li/Na)(2)CO3 (SDC-carbonate, abbr. SCC) composites is systematically investigated. With the addition of carbonate, the nanoparticles of ceria are well preserved after heat-treatment. The relative densities of SCC pellets increase as the carbonate content increases or sintering temperature rises. Especially, the relative density of SCC2 sintered at 900 degrees C is higher than that of pure SDC sintered at 1350 degrees C. Both the AC conductivity and DC oxygen ionic conductivity are visibly improved compared with the single phase SDC electrolyte. Among the composites, SDC-20 wt% (Li/Na)(2)CO3 (SCC20) presents high dispersion, relative small particle size, and the dense microstructure. The optimized microstructure brings the best ionic conductivity and fuel cell performance. It is hoped that the results can contribute the understanding of the role of carbonate in the composite materials and highlight their prospective application.

  • 19. Chutichai, Bhawasut
    et al.
    Im-Orb, Karittha
    Alvfors, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Arpornwichanop, Amoynchai
    Design of an integrated biomass gasification and proton exchange membrane fuel cell system under self-sustainable conditions: Process modification and heat-exchanger network synthesis2017In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 1, p. 448-458Article in journal (Refereed)
    Abstract [en]

    The design and analysis of an integrated biomass gasification and PEMFC system to generate heat and power demand for residential applications are presented in this study. Two biomass gasification configurations using sawdust as a feedstock are considered: air steam biomass gasification (AS-BG-PEMFC) and steam-only biomass gasification (SO-BG-PEMFC). The biomass processing consists of a biomass gasification which is used to produce H-2-rich gas (syngas), followed by high- and low-temperature shift reactors and a preferential oxidation reactor. Pinch analysis is performed to evaluate and design a heat-exchanger network in the two biomass gasification systems. The remaining useful heat is recovered and employed for a reactant preparation step and for a heating utility system in a household. The simulation results indicate that the SO-BG-PEMFC generates syngas with a greater H2 content than the AS-BG-PEMFC, resulting in higher fuel processor and electric efficiencies. However, the AS-BG-PEMFC provides a higher thermal efficiency because a high temperature gaseous product is obtained, and more energy is thereby recovered to the system. The total heat and power efficiencies of the AS-BG-PEMFC and the SO-BG-PEMFC are 83% and 70%, respectively. The Sankey diagram of energy flows reveals that the performance improvement depends entirely on the utilization of useful energy in the exhaust gas.

  • 20. Danwittayakul, S.
    et al.
    Dutta, Joydeep
    Center of Excellence in Nanotechnology, Asian Institute of Technology, Thailand.
    Zinc oxide nanorods based catalysts for hydrogen production by steam reforming of methanol2012In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, no 7, p. 5518-5526Article in journal (Refereed)
    Abstract [en]

    Zinc oxide (ZnO) nanorods were epitaxially grown on porous cordierite support by a hydrothermal process and utilized for catalyzing methanol steam reforming (MSR) reaction. Catalytic activity of ZnO nanorods for MSR process was correlated to the terminated surfaces of ZnO crystallites. Copper (Cu), palladium (Pd) and gold (Au) nanoparticles infused ZnO nanorods were prepared by in-situ precipitation of the metals on the nanorods. 28% hydrogen selectivity was observed with Cu/ZnO nanorods (Cu/10Zn), while Pd/ZnO nanorods and (Pd/10Zn) showed slightly lower activity. Higher catalytic activity of copper and palladium impregnated ZnO nanorods can be attributed to the synergistic combination of bimetallic oxides. In contrast, Au/ZnO nanorods (Au/10Zn) showed very high activity for methanol dehydrogenation and higher than 97% methanol conversion was achieved for operating temperatures as low as 200 degrees C.

  • 21. Dascomb, John
    et al.
    Krothapalli, Anjaneyulu
    Fakhrai, Reza
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Thermal conversion efficiency of producing hydrogen enriched syngas from biomass steam gasification2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 27, p. 11790-11798Article in journal (Refereed)
    Abstract [en]

    This paper presents the results from an experimental study on the energy conversion efficiency of producing hydrogen enriched syngas through uncatalyzed steam biomass gasification. Wood pellets were gasified using a 100 kWth fluidized bed gasifier at temperatures up to 850 degrees C. The syngas hydrogen concentration and cold gas efficiency were found to increase with both bed temperature and steam to biomass weight ratio, reaching a maximum of 51% and 124% respectively. The overall energy conversion to syngas (based on heating value) also increased with bed temperature but was inversely proportional to the steam to biomass ratio. The maximum energy conversion to syngas was found to be 68%. The conversion of energy to hydrogen (by heating value) increased with gasifier temperature and gas residence time, but was found to be independent of the S/B ratio. The maximum conversion of all energy sources to hydrogen was found to be 25%.

  • 22. Davoodi, Ali
    et al.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Corrosion Science.
    Parvizi, Reza
    Minuscule device for hydrogen generation/electrical energy collection system on aluminum alloy surface2011In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, no 4, p. 2855-2859Article in journal (Refereed)
    Abstract [en]

    Cogeneration of hydrogen and electrical energy in a single system is still a challenging issue. In this work, in a micro scale, a novel miniaturized system is introduced to capture the electrical energy of produced hydrogen on aluminum alloy by using an ultra-microelectrode based on scanning electrochemical microscopy (SECM). Sophisticated nanosize atomic force microscopy (AFM) based SECM probe could collect the electrochemical current close proximity distance from the aluminum surface to attain the highest possible current efficiency. Various collected current levels were associated to the aluminum microstructure constituents. It is expected that future development in instrumentation could principally facilitate SECM as a tool for hydrogen economy.

  • 23. Deng, Hui
    et al.
    Feng, Chu
    Zhang, Wei
    Mi, Youquan
    Wang, Xunying
    Dong, Wenjing
    Wang, Baoyuan
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Hubei University, China.
    The electrolyte-layer free fuel cell using a semiconductor-ionic Sr2Fe1.5Mo0.5O6-delta - Ce0.8Sm0.2O2-delta composite functional membrane2017In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 39, p. 25001-25007Article in journal (Refereed)
    Abstract [en]

    Commercial double Perovskite Sr2Fe1.5Mo0.5O6-delta (SFM), a high performance and redox stable electrode material for solid oxide fuel cell (SOFC), has been used for the electrolyte (layer)-free fuel cell (EFFC) and also as the cathode for the electrolyte based SOFC in a comprehensive study. The EFFC with a homogeneous mixture of Ce0.8Sm0.2O2-delta (SDC) and SFM achieved a higher power density (841 mW cm(-2)) at 550 degrees C, while the SDC electrolyte based SOFC, using the SDC-SFM composite as cathode, just reached 326 mW cm(-2) at the same temperature. The crystal structure and the morphology of the SFM-SDC composite were characterized by X-ray diffraction analysis (XRD), and scanning electron microscope (SEM), respectively. The electrochemical impedance spectroscopy (EIS) results showed that the charge transfer resistance of EFFCs were much lower than that of the electrolyte-based SOFC. To illustrate the operating principle of EFFC, we also conducted the rectification characteristics test, which confirms the existence of a Schottky junction structure to avoid the internal electron short circuiting. This work demonstrated advantages of the semiconductor-ionic SDC-SFM material for advanced EFFCs.

  • 24. Deng, Hui
    et al.
    Zhang, Wei
    Wang, Xunyin
    Mi, Youquan
    Dong, Wenjin
    Tan, Wenyi
    Zhu, Binzhu
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science, Hubei University, Wuhan, Hubei, 430062, PR China.
    An ionic conductor Ce0.8Sm0.2O2_(delta) (SDC) and semiconductor Sm0.5Sr0.5CoO3 (SSC) composite for high performance electrolyte-free fuel cell2017In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 42, no 34, p. 22228-22234Article in journal (Refereed)
    Abstract [en]

    An advanced electrolyte-free fuel cell (EFFC) was developed. In the EFFC, a composite layer made from a mixture of ionic conductor (Ce0.8Sm0.2O2_(delta), SDC) and semiconductor (Sm0.5Sr0.5CoO3, SSC) was adopted to replace the electrolyte layer. The crystal structure, morphology and electrical properties of the composite were characterized by X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and electrochemical impedance spectrum (EIS). Various ratios of SDC to SSC in the composite were modulated to achieve balanced ionic and electronic conductivities and good fuel cell performances. Fuel cell with an optimum ratio of 3SDC:2SSC (wt.%) reached the maximum power density of 741 mW cm(-2) at 550 degrees C. The results have illuminated that the SDC-SCC layer, similar to a conventional cathode, can replace the electrolyte to make the EFFC functions when the ionic and electronic conductivities were balanced.

  • 25. Dong, Hanwu
    et al.
    Kiros, Yohannes
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Noreus, Dag
    An air-metal hydride battery using MmNi(3.6)Mn(0.4)Al(0.3)Co(0.7) in the anode and a perovskite in the cathode2010In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 35, no 9, p. 4336-4341Article in journal (Refereed)
    Abstract [en]

    Hydrogen storage alloy MmNi(3.6)Mn(0.4)Al(0.3)Co(0.7) (MH) was tested as anode material in a metal hydride-air cell. The cathode was a non-noble metal air electrode based on a mixture of perovskite and pyrolyzed macrocycles on carbon. Polarization and discharge capacities of the electrodes were measured and compared at 22 degrees C and 40 degrees C using air or oxygen at the cathode. Discharge capacity reaching 330 mAh/g MH with pure oxygen at 40 degrees C and 305 mAh/g MH with air at 22 degrees C were obtained. Power densities and/or energy densities were found to significantly depend on the increase of the electrode kinetics on both the ORR (oxygen reduction reaction) and HOR (hydrogen oxidation reaction). However, for air electrode, an increase of oxygen concentration by using pure oxygen gas plays a more important role than an 18 degrees C temperature increase. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

  • 26.
    Dou, Maofeng
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Baldissera, Gustavo
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Multiscale Materials Modelling.
    Persson, Clas
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Multiscale Materials Modelling.
    ZnO-InN nanostructures with tailored photocatalytic properties for overall water-splitting2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 36, p. 16727-16732Article in journal (Refereed)
    Abstract [en]

    ZnO-based electrodes for one-step photocatalytic water splitting are designed by incorporating InN. The electronic and optical properties of (ZnO)(1-x)(InN)(x) alloys and ZnO with InN-like cluster formations ZnO:(InN)(x) are analyzed by means of first-principles approaches. We calculate the energy gaps E-g, the band-edge energies relative to the vacuum level, and the optical absorption, employing the GW(o) method to describe single-particle excitations and the Bethe-Salpeter equation to model the two-particle exciton interactions. For ZnO and InN, the valence-band maximum (VBM) is E-VBM approximate to -7.3 and -5.7 eV, and the energy gap is E-g approximate to 3.3 and 0.7 eV, respectively. Incorporating InN into ZnO, the random (ZnO)(1-x)(InN)(x) alloys up-shifts the VBM and down-shifts the conduction-band minimum (CBM). In addition, the presence of InN-like clusters enhances this effect and significantly narrows the band gap. For instance, the VBM and the energy gap for 12.5% InN are E-VBM approximate to -6.5 and -6.1 eV, and E-g approximate to 2.2 and 1.9 eV for the alloy and the cluster structure, respectively. This impact on the electronic structure favors thus visible light absorption. With proper nanoclusters, the band edges straddle the redox potential levels of H+/H-2 and O-2/H2O, suggesting that ZnO-InN nanostructures can enhance the photocatalytic activity for overall solar-driven water splitting.

  • 27.
    Eriksson, Björn
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Grimler, Henrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Carlson, Annika
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Ekström, Henrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Wreland Lindström, Rakel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Applied Electrochemistry.
    Quantifying water transport in anion exchange membrane fuel cells2019In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 44, no 10, p. 4930-4939Article in journal (Refereed)
    Abstract [en]

    Sufficient water transport through the membrane is necessary for a well-performing anion exchange membrane fuel cell (AEMFC). In this study, the water flux through a membrane electrode assembly (MEA), using a Tokuyama A201 membrane, is quantified using humidity sensors at the in- and outlet on both sides of the MEA. Experiments performed in humidified inert gas at both sides of the MEA or with liquid water at one side shows that the aggregation state of water has a large impact on the transport properties. The water fluxes are shown to be approximately three times larger for a membrane in contact with liquid water compared to vaporous. Further, the flux during fuel cell operation is investigated and shows that the transport rate of water in the membrane is affected by an applied current. The water vapor content increases on both the anode and cathode side of the AEMFC for all investigated current densities. Through modeling, an apparent water drag coefficient is determined to −0.64, indicating that the current-induced transport of water occurs in the opposite direction to the transport of hydroxide ions. These results implicate that flooding, on one or both electrodes, is a larger concern than dry-out in an AEMFC.

  • 28.
    Fan, Liangdong
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Chen, Mingming
    Tianjin University, China.
    Wang, Chengyang
    Tianjin University, China.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Pr2NiO4–Ag composite cathode for low temperature solid oxide fuel cells with ceria-carbonate composite electrolyte2012In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, no 24, p. 19388-19394Article in journal (Refereed)
    Abstract [en]

    Pr2NiO4-Ag composite was synthesized and evaluated as cathode component for low temperature solid oxide fuel cells based on ceria-carbonate composite electrolyte. X-ray diffraction analysis reveals that the formation of a single phase K2NiF4-type structure occurs at 1000 °C and Pr2NiO4-Ag composite shows chemically compatible with the composite electrolyte. Symmetrical cells impedance measurements prove that Ag displays acceptable electrocatalytic activity toward oxygen reduction reaction at the temperature range of 500-600 °C. Single cells with Ag active component electrodes present better electrochemical performances than those of Ag-free cells. An improved maximum power density of 695 mW cm-2 was achieved at 600 °C using Pr 2NiO4-Ag composite cathode, with humidified hydrogen as fuel and air as the oxidant. Preliminary results suggest that Pr 2NiO4-Ag composite could be adopted as an alternative cathode for low temperature solid oxide fuel cells.

  • 29.
    Fan, Liangdong
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Wang, Chengyang
    Chemical engineering and technology.
    Chen, Mingming
    Di, Jing
    Zheng, Jiaming
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM).
    Potential low-temperature application and hybrid-ionic conducting property of ceria-carbonate composite electrolytes for solid oxide fuel cells2011In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, no 16, p. 9987-9993Article in journal (Refereed)
    Abstract [en]

    Ceria-carbonate composite materials have been widely investigated as candidate electrolytes for solid oxide fuel cells operated at 300-600 degrees C. However, fundamental studies on the composite electrolytes are still in the early stages and intensive research is demanded to advance their applications. In this study, the crystallite structure, microstructure, chemical activity, thermal expansion behavior and electrochemical properties of the samaria doped ceria-carbonate (SCC) composite have been investigated. Single cells using the SCC composite electrolyte and Ni-based electrodes were assembled and their electrochemical performances were studied. The SCC composite electrolyte exhibits good chemical compatibility and thermal-matching with Ni-based electrodes. Peak power density up to 916 mW cm(-2) was achieved at 550 degrees C, which was attributed to high electrochemical activity of both electrolyte and electrode materials. A stable discharge plateau was obtained under a current density of 1.5 A cm(-2) at 550 degrees C for 120 min. In addition, the ionic conducting property of the SCC composite electrolyte was investigated using electrochemical impedance spectroscopy technique. It was found that the hybrid-ionic conduction improves the total ionic conductivity and fuel cell performance. These results highlight potential low-temperature application of ceria-carbonate composite electrolytes for solid oxide fuel cells.

  • 30.
    Fan, Liangdong
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhang, Hongjuan
    Chen, Mingming
    Wang, Chengyang
    Wang, Hao
    Singh, Manish
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Electrochemical study of lithiated transition metal oxide composite as symmetrical electrode for low temperature ceramic fuel cells2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 26, p. 11398-11405Article in journal (Refereed)
    Abstract [en]

    In this work, Lithiated NiCuZnOx (LNCZO) composite is synthesized and evaluated as a potential symmetrical electrode for ceria-carbonate composite electrolyte based low temperature ceramic fuel cells. Its crystal structures, the hydrogen oxidation/oxygen reduction electrochemical activities and fuel cell performances are systematically examined on the symmetrical cell configuration. Nano crystallite particles in the form of composite are observed for these oxides. The LNCZO shows relatively high catalytic activities for hydrogen oxidation and oxygen reduction reaction according to the electrochemical impedance spectroscopy measurements. A remarkable low oxygen reduction activation energy of 42 kJ mol(-1) is obtained on the LNCZO/ceria-carbonate composite, demonstrating excellent electro-catalytic activity. Especially, the catalytic activity can be further improved in the presence of water in the cathode chamber. The results show that the lithiated transition metal oxide composite is a promising symmetrical electrode for ceria-carbonate electrolyte and composite approach might a probable solution to develop super-performance electrodes for reduced temperature ceramic fuel cells.

  • 31.
    Gao, Zhan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Mao, Zongqiang
    Wang, Cheng
    Liu, Zhixiang
    Novel SrTi(x)Co(1-x)O(3-delta) cathodes for low-temperature solid oxide fuel cells2011In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, no 12, p. 7229-7233Article in journal (Refereed)
    Abstract [en]

    The SrTi(x)Co(1-x)O(3-delta) (STC, x = 0.05, 0.1, 0.15, 0.2) perovskite-type oxides synthesized by the polymerized complex (PC) method have been investigated as cathode materials for low-temperature solid oxide fuel cells (SOFCs) with composite electrolyte for the first time. Thermogravimetry differential thermal analysis (TG-DTA) shows the crystallization of SrTi(0.1)Co(0.9)O(3-delta) occurs at 780 degrees C. The oxides have been stabilized to be a cubic perovskite phase after the B-site is doped with Ti ion. The maximum power density reaches as high as 613 mW cm(-2) at 600 degrees C for SOFC with SrTi(0.2)Co(0.8)O(3-delta) cathode. The maximum power densities increase with the increasing Ti content in the cathode, which can be attributed to the enhancement of conductivity and electrocatalytic activity. The stability of the fuel cell with SrTi(0.1)Co(0.9)O(3-delta) cathode has been examined for 18 h at 600 degrees C. Only a slight decline in the cell performance can be observed with increasing time. The high performance cathodes together with the low-cost fabrication technology are highly encouraging for development of low-temperature SOFCs.

  • 32. Gao, Zhan
    et al.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Mao, Zongqiang
    Wang, Cheng
    Liu, Zhixiang
    Preparation and characterization of Sm0.2Ce0.8O1.9/Na2CO3 nanocomposite electrolyte for low-temperature solid oxide fuel cells2011In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 36, no 6, p. 3984-3988Article in journal (Refereed)
    Abstract [en]

    Sm0.2Ce0.8O1.9 (SDC)/Na2CO3 nanocomposite synthesized by the co-precipitation process has been investigated for the potential electrolyte application in low-temperature solid oxide fuel cells (SOFCs). The conduction mechanism of the SDC/Na2CO3 nanocomposite has been studied. The performance of 20 mW cm(-2) at 490 degrees C for fuel cell using Na2CO3 as electrolyte has been obtained and the proton conduction mechanism has been proposed. This communication demonstrates the feasibility of direct utilization of methanol in low-temperature SOFCs with the SDC/Na2CO3 nanocomposite electrolyte. A fairly high peak power density of 512 mW cm(-2) at 550 degrees C for fuel cell fueled by methanol has been achieved. Thermodynamical equilibrium composition for the mixture of steam/methanol has been calculated, and no presence of C is predicted over the entire temperature range. The long-term stability test of open circuit voltage (OCV) indicates the SDC/Na2CO3 nanocomposite electrolyte can keep stable and no visual carbon deposition has been observed over the anode surface. Copyright (C) 2011, Hydrogen Energy Publications, LLC.

  • 33.
    Granlund, Moa Z.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Görke, Oliver
    Pfeifer, Peter
    Pettersson, Lars J.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Comparison between a micro reactor with multiple air inlets and a monolith reactor for oxidative steam reforming of diesel2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 31, p. 18037-18045Article in journal (Refereed)
    Abstract [en]

    Abstract In order to lower the emission from idling heavy-duty trucks auxiliary power units can be implemented. Due to limited space available on-board the truck the units needs to be both efficient and compact. One alternative for these units is a fuel cell supplied with hydrogen from a fuel reformer. Today, mostly monolithic reactors are used in the field of oxidative steam reforming of fuels, which has some challenges that need to be addressed before a possible breakthrough occurs on the market. One is the temperature gradient developed over the length of the monolith as a consequence of the sequential reactions. This could be improved by using a metallic micro reactor with better heat integration between the reaction zones and further improving the integration with multiple air inlets along the catalytic bed. The aim with this study was to compare a conventional monolith reactor for oxidative steam reforming of fuel with a novel micro reactor design where air was dosed at four different positions along the reactor channels. The experiments were not necessarily conducted autothermal, i.e. a heating jacket was applied for operation.

  • 34. Guo, Z.
    et al.
    Sa, B.
    Pathak, B.
    Zhou, J.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Sun, Z.
    Band gap engineering in huge-gap semiconductor SrZrO3 for visible-light photocatalysis2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 5, p. 2042-2048Article in journal (Refereed)
    Abstract [en]

    Using SrZrO3 (SZO, the intrinsic band gap being 5.6 eV) as an example, we have investigated the design principles for huge-gap semiconductors with band gap larger than 5 eV for the application of efficient visible-light driven photocatalysts for splitting water into hydrogen. Based on the hybrid density function calculations, the electronic structures of mono-doped and co-doped SZO are investigated to obtain design principles for improving their photocatalytic activity in hydrogen generation. The cationic-anionic co-doping in SZO could reduce the band gap significantly and its electronic band position is excellent for the visible-light photocatalysis. This work reports a new type of candidate material for visible-light driven photocatalysis, i.e., huge-gap semiconductors with band gap larger than 5 eV. Furthermore, based on the present results we have proposed the design principles for band gap engineering that provides general guideline for other huge-gap semiconductors.

  • 35.
    Gustavsson, John
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    In-situ activation of hydrogen evolution in pH-neutral electrolytes by additions of multivalent cations2012In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 37, no 12, p. 9496-9503Article in journal (Refereed)
    Abstract [en]

    Activation of the hydrogen evolution reaction (HER) in close to pH-neutral electrolytes can be achieved by addition of trivalent cations. This activation has been investigated using steady state polarization, electrochemical impedance spectroscopy (EIS) and chemical analysis of cathode films for yttrium. Several multivalent cations were included in this study, such as Al(III), Mg(II), Y(III), Sm(III), La(III) and Sc(III). In general the more acidic the metal ions the larger is the activation. Metal hydroxide films formed in the alkaline diffusion layer at the cathode surface can have a negative impact on the magnitude of this activation, and therefore complicate the interpretation of the results. The activation corresponds to a transport of metal ion complexes to the electrode surface and the reduction of bound ligand water to form hydrogen.

  • 36.
    Haraldsson, Kristina
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Folkesson, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Saxe, Maria
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Alvfors, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    A First Report on the Attitude towards Hydrogen Fuel Cell Buses in Stockholm2006In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 31, no 3, p. 317-325Article in journal (Refereed)
    Abstract [en]

    Surveys of the attitude towards hydrogen fuel cell buses among passengers and bus drivers were performed in Stockholm during the autumn of 2004. Another field survey of the attitude of the fuel cell bus passengers is planned towards the end of the CUTE Stockholm project, i.e. during the autumn of 2005.

    The main results from the surveys are:

    People are generally positive towards fuel cell buses and feel safe with the technology.

    Newspapers and bus stops are where most people get information about the buses.

    The passengers, furthermost those above the age of 40, desire more information about fuel cells and hydrogen.

    The drivers are generally positive to the fuel cell bus project.

    Although the environment is rated as an important factor, 64% of the bus passengers were not willing to pay a higher fee if more fuel cell buses were to be used.

  • 37.
    Hedström, Lars
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Tingelöf, Thomas
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Alvfors, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Experimental results from a 5 kW PEM fuel cell stackoperated on simulated reformate from highly dilutedhydrocarbon fuels: Efficiency, dilution, fuel utilisation,CO poisoning and design criteria2009In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, no 34, p. 1508-1514Article in journal (Refereed)
    Abstract [en]

    The present article analyses the effects of dilute biogas on efficiency, fuel utilisation, dynamics, control strategy, and design criteria for a polymer electrolyte fuel cell (PEFC) system. The tested fuel compositions are exemplified by gas compositions that could be attained within various Swedish biofuel demonstration projects. Experimental data which can serve as a basis for design of PEFC biogas systems operating in load-following, or steady-state mode, are reported for a 5 kW PEFC stack.

  • 38. Hu, Huiging
    et al.
    Lin, Qizhao
    Zhu, Zhigang
    Liu, Xiangrong
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Time-dependent performance change of single layer fuel cell with Li0.4Mg0.3Zn0.3O/Ce0.8Sm0.2O2-delta composite2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 20, p. 10718-10723Article in journal (Refereed)
    Abstract [en]

    A Large-size engineering single layer fuel cell (SLFC) consisting of a nano-structured Li0.4Mg0.3Zn0.3O2-delta/Ce0.8Sm0.2O2-delta (LMZSDC) composite with an active area of 25 cm(2) (6 cm x 6 cm x 0.1 cm) is successfully fabricated. The SLFC is evaluated by testing the cell durability with a time-dependent degradation using an H-2 fuel and an air oxidant at 600 degrees C for over 120 h. A maximum power of 12.8 W (512 mW cm(-2)) is achieved at 600 degrees C. In the initial operation stage around 50 h, the cell's performance decreases from 12.8 to 11.2 W; however, after this point, the performance was consistently stable, and no significant degradation is observed in the current density or the cell performance. The device performed excellently at low temperatures with a delivered power output of more than 250 mW cm(-2) at a temperature as low as 400 degrees C. By curve fitting the X-ray photoelectron spectroscopy (XPS) results, the ratio of Ce3+/(Ce3++Ce4+) before and after the long-time operation is analyzed. The ratio increased from 28.2% to 31.4% in the electrolyte which indicates a reduction occurs in the beginning operation that causes an initial performance loss for the device power output and OCV. Electrochemical impedance analyses indicate that the LMZSDC had a high ionic transport, and the device had quick dynamic processes and, thus, a high fuel cell performance. The LMZSDC is a new type of ionic material that has been successfully applied to SLFCs.

  • 39.
    Hu, Lan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Operating the nickel electrode with hydrogen-lean gases in the molten carbonate electrolysis cell (MCEC)2016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 41, p. 18692-18698Article in journal (Refereed)
    Abstract [en]

    If a molten carbonate electrolysis cell (MCEC) is applied for fuel gas production it is important to know the polarization of the nickel electrode when operated at low concentration of hydrogen. Thus, the electrochemical performance of the Ni electrode was investigated under hydrogen-lean gases containing 1/24.5/24.5/50%, 1/49.5/24.5/25%, 1/24.5/49.5/25% and 1/49.5/49.5/0% H-2/CO2/H2O/N-2 in the temperature range of 600-650 degrees C and was then compared to the reference case with 25/25/25/25% H-2/CO2/H2O/N-2. The electrochemical measurements included polarization curve coupled with current interrupt, and electrochemical impedance spectroscopy. Polarization resistances of the Ni electrode obtained by the two different techniques agreed well. For the inlet gases containing low amounts of hydrogen the Ni electrode exhibited higher polarization losses than when using the reference case in the electrolysis cell. The electrochemical impedance measurements showed that both charge-transfer and mass-transfer polarizations were higher for hydrogen-lean gases at all measured temperatures. Except under the condition with 1/49.5/49.5% H-2/CO2/H2O at 650 degrees C, the Ni electrode exhibited lower mass-transfer polarization when compared to the reference case. Furthermore, the mass-transfer polarization was strongly dependent on temperature under H-2-lean gases, differing from the reference case when the temperature has almost no effect on mass-transfer polarization. The activation energy for hydrogen production was calculated to be in the range of 69 -138 kJ mol(-1) under all measured gases, indicating that the Ni electrode is under kinetic and/or mixed control in the MCEC.

  • 40.
    Hu, Lan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Rexed, Ivan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Electrochemical performance of reversible molten carbonate fuel cells2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 23, p. 12323-12329Article in journal (Refereed)
    Abstract [en]

    The electrochemical performance of a state-of-the-art molten carbonate cell was investigated in both fuel cell (MCFC) and electrolysis cell (MCEC) modes by using polarization curves and electrochemical impedance spectroscopy (EIS). The results show that it is feasible to run a reversible molten carbonate fuel cell and that the cell actually exhibits lower polarization in the MCEC mode, at least for the short-term tests undertaken in this study. The Ni hydrogen electrode and the NiO oxygen electrode were also studied in fuel cell and electrolysis cell modes under different operating conditions, including temperatures and gas compositions. The polarization of the Ni hydrogen electrode turned out to be slightly higher in the electrolysis cell mode than in the fuel cell mode at all operating temperatures and water contents. This was probably due to the slightly larger mass-transfer polarization rather than to charge-transfer polarization according to the impedance results. The CO2 content has an important effect on the Ni electrode in electrolysis cell mode. Increasing the CO2 content the Ni electrode exhibits slightly lower polarization in the electrolysis cell mode. The NiO oxygen electrode shows lower polarization loss in the electrolysis cell mode than in the fuel cell mode in the temperature range of 600-675 degrees C. The impedance showed that both charge-transfer and mass-transfer polarization of the NiO electrode are lower in the electrolysis cell than in the fuel cell mode.

  • 41. Hussain, Tanveer
    et al.
    De Sarkar, Abir
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Functionalization of hydrogenated graphene by polylithiated species for efficient hydrogen storage2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 6, p. 2560-2566Article in journal (Refereed)
    Abstract [en]

    The hydrogen (H-2) storage capacity of defected graphane (CH) functionalized by polylithiated species CLi3 and CLi4 has been investigated by means of first-principles DFT calculations. The stability and electronic structures of these potential H-2 storage materials have also been studied. The binding of these lithium rich species (CLi3, CLi4) to the CH sheet has been found to be strong enough to avoid clustering. The nature of bonding in C-Li and C-C has been revealed by Bader charge analysis. It has been found that when both sides of CH sheet are functionalized by polylithiated species, a storage capacity of more than 13 wt % can be achieved with adsorption energies of H-2 in the range of 0.25 eV-0.35 eV, which is suitable for an efficient H-2 storage.

  • 42. Ivanov, M. F.
    et al.
    Kiverin, A. D.
    Yakovenko, I. S.
    Liberman, Mikhail A.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Hydrogen-oxygen flame acceleration and deflagration-to-detonation transition in three-dimensional rectangular channels with no-slip walls2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 36, p. 16427-16440Article in journal (Refereed)
    Abstract [en]

    Hydrogen-oxygen flame acceleration and the transition from deflagration to detonation (DDT) in channels with no-slip walls are studied using high resolution simulations of 3D reactive Navier-Stokes equations, including the effects of viscosity, thermal conduction, molecular diffusion, real equation of state and detailed (reduced) chemical reaction mechanism. The acceleration of the flame propagating from the closed end of a channel, which is a key factor for understanding of the mechanism of DDT, is thoroughly studied. The three dimensional modeling of the flame acceleration and DDT in a semi-closed rectangular channel with cross section 10 x 10 mm and length 250 mm confirms validity of the mechanism of deflagration-to-detonation transition, which was proposed earlier theoretically and verified using 2D simulations. We show that 3D model contrary to 2D models allows to understand clearly the meaning of schlieren photos obtained in experimental studies. The "numerical schlieren" and "numerical shadowgraph" obtained using 3D calculations clarify the meaning of the experimental schlieren and shadow photos and some earlier misinterpretations of experimental data.

  • 43. Javed, Muhammad Sufyan
    et al.
    Raza, Rizwan
    Ahsan, Zishan
    Rafique, M. Shahid
    Shahzadi, Shamaila
    Shaukat, S. F.
    Shaheen, Nusrat
    Khalid, Muhammad Saeed
    Chengou, Hu
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Hubei Univiversitym China.
    Electrochemical studies of perovskite cathode material for direct natural gas fuel cell2016In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, no 4, p. 3072-3078Article in journal (Refereed)
    Abstract [en]

    Natural gas is the most promising renewable energy source and its widespread availability ensured its importance for early applications in stationary fuel cells as a reliable and low cost fuel. Therefore it is very important to efficiently utilization of natural gas in low temperature fuel cells. Herein, we demonstrate the synthesis of perovskite material of Yttrium doped Sr0.92FexTi1-xO3-delta (x = 0.25, 030) (YSFT) by solid state reaction method and further investigated as a new cathode material for a low temperature solid oxide fuel cell fueled by natural gas. The YSFT is characterized by X-ray powder diffraction, Brunauer-Emmett-Teller and scanning electron microscopy. The perovskite structure is achieved at relatively low temperature (850 degrees C). The average crystalline size is found 28 nm and 36 nm for x = 0.25 and 0.30 respectively. TGA results showed the lattice oxygen loss of YSFT is about 0.206% in its original weight in the temperature range of 25-1000 degrees C. The maximum electronic conductivities of 2.3 Scm(-1) and 2.07 Scm(-1) are achieved for x = 025 and x = 0.30 at 550 degrees C in air atmosphere respectively. It is observed that the oxygen reduction is enhanced due to the perovskite crystal structure and oxygen vacancies play an important role in the redox reaction to improve the performance of fuel cell. The YSFT perovskite cathode material based fuel cell with natural gas have achieved the power density of 250 mWcm(-2) for x = 025 at 550 degrees C. The fuel cell device has demonstrated very stable results by running continuously for 5 h with domestic available natural gas. 

  • 44.
    Jing, Yifu
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Department of Applied Physics, Aalto University School of Science, Finland .
    Ma, Ying
    Patakangas, Janne
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Johnsson, Mats
    Cura, M. Erkin
    Lund, Peter
    Enhanced conductivity of SDC based nanocomposite electrolyte by spark plasma sintering2014In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 39, no 26, p. 14391-14396Article in journal (Refereed)
    Abstract [en]

    Recently, ceria-based nanocomposites have been considered as promising electrolyte candidates for low-temperature solid oxide fuel cells (LTSOFC) due to their dual-ion conduction and excellent performance. However, the densification of these composites remains a great concern since the relative low density of the composite electrolyte is suspected to deteriorate the durability of fuel cell. In the present study, the ionic conductivity of two kinds of SDC-based nanocomposite electrolytes processed by spark plasma sintering (SPS) method was investigated, and compared to that made by conventional cold pressing followed by sintering (normal processing way). The density of solid electrolyte can reach higher than 95% of the theoretical value after SPS processing, while the relative density of the electrolyte pellets by normal processing way can hardly approach 75%. The structure and morphology of the sintered pellets were characterized by XRD and SEM. The ionic conductivity of samples was measured by electrochemical impedance spectroscopy (EIS). The results showed that the ionic conductivity of the two kinds of electrolytes treated with SPS was significantly enhanced, compared with the electrolyte pellets processed through the conventional method. The profile of impedance curve of the electrolytes was altered as well. This study demonstrates that the conductivity of SDC based nanocomposite electrolyte can be further improved by adequate densification process.

  • 45.
    Khan, M. Ajmal
    et al.
    Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Zhejiang Prov Key Lab Magnet Mat & Applicat Techn, CAS Key Lab Magnet Mat & Devices, Ningbo 315201, Zhejiang, Peoples R China.;COMSATS Inst Informat Technol, Dept Phys, Lahore 5400, Pakistan..
    Xu, Cheng
    Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Zhejiang Prov Key Lab Magnet Mat & Applicat Techn, CAS Key Lab Magnet Mat & Devices, Ningbo 315201, Zhejiang, Peoples R China..
    Song, Zhenlun
    Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, Zhejiang Prov Key Lab Magnet Mat & Applicat Techn, CAS Key Lab Magnet Mat & Devices, Ningbo 315201, Zhejiang, Peoples R China..
    Raza, Rizwan
    COMSATS Inst Informat Technol, Dept Phys, Lahore 5400, Pakistan..
    Ahmad, Muhammad Ashfiq
    COMSATS Inst Informat Technol, Dept Phys, Lahore 5400, Pakistan..
    Abbas, Ghazanfar
    COMSATS Inst Informat Technol, Dept Phys, Lahore 5400, Pakistan..
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Synthesize and characterization of ceria based nano-composite materials for low temperature solid oxide fuel cell2018In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, no 12, p. 6310-6317Article in journal (Refereed)
    Abstract [en]

    The present study is focused on ceria based mixed (ionic and electronic conductor) composite Al0.05Ni0.1Ti0.05Zn0.80-SDC (ATZN-SDC) oxide material was prepared by solid state reaction, which can be used as anode materials for solid oxide fuel cell. The effect of Ti and Al oxides were analyzed on the NiZn-SDC composite with respect to its conductivity and catalytic activity in hydrogen atmosphere. The average crystallite size of the composite was found to be 40-100 nm by XRD and SEM. The DC conductivity was determined by 4-probe technique. The electrochemical impedance spectrum (EIS) was also examined in hydrogen atmosphere within a temperature range of 350-550 degrees C. The maximum power density 370 mW/cm(2) was achieved at 650 degrees C.

  • 46.
    Kiros, Yohannes
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Myrén, Carin
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Schwartz, S.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Sampathrajan, A
    Tamil Nadu Agricultural University.
    Ramanathan, M
    Tamil Nadu Agricultural University.
    Electrode R&D, stack design and performance of biomass-based alkaline fuel cell module1999In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 24, p. 549-564Article in journal (Refereed)
    Abstract [en]

    Electrode formulations with di}erent materials and manufacturing techniques were tested electrochemically in order to assess their stability and activity in long!term operations. Cathode electrocatalysts such as CoTPP, Ca0.9La0.1MnO3 and Pt-Co alloys were incorporated in high surface area carbons and operated at a constant load of 100 mA cm-2 80C and an electrolyte concentration of 6M KOH. Similarly, anode catalysts with Pt-Pd bimetallic combinations were also tested and ascertained in half!cell measurements. Surface area measurements and Transmission Electron Microscopy (TEM) analyses were carried out both before and after the electrochemical test procedures. The electrodes were incorporated into a seven and two cell module design of the external and internal manifolding types and the experiences gained from these design principles are described, respectively. Furthermore, a biomass fed AFC module with all the system descriptions, steps, and a demonstration layout of producer gas to alkaline fuel cell are examined and discussed. Wood charcoal and agro-residues were used as feedstock and as a primary fuel. Power output of the different feedstock in a producer gas fed alkaline fuel cell has the shown potentiality and effciency to be applied as a stand alone power generator.

  • 47.
    Kortsdottir, Katrin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Wreland Lindström, Rakel
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    The influence of ethene impurities in the gas feed of a PEM fuel cell2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 38, no 1, p. 497-509Article in journal (Refereed)
    Abstract [en]

    Hydrogen produced by reforming may contain traces of hydrocarbon contaminants. These traces may affect the performance and lifetime of a fuel cell run on reformate-hydrogen. This study treats the influence of low concentrations of ethene on the adsorption and deactivation chemistry in a polymer electrolyte membrane (PEM) fuel cell. The study employs mainly cyclic voltammetry accompanied with an on-line mass spectrometer to analyse the outlet gas. Results from adsorption and desorption, by either oxidation or reduction, are presented, and the influence of adsorption potential, temperature and humidity and the presence of hydrogen are discussed. The results show that the adsorption of traces of ethene in a fuel cell is highly dependent on adsorption potential and that ethene adsorbs on Pt catalyst in a limited potential window only. Ethene cannot displace adsorbed H and is oxidised already at potentials of 0.6 V versus RHE at 80°C, where the only detectable product is CO 2. A considerable part of ethene adsorbed at potentials above the hydrogen adsorption/desorption region can be reduced at low potentials and is desorbed as methane or ethene. Overall, the effect of low concentrations of ethene in the hydrogen feed on fuel cell performance is minimal, and no significant loss in cell voltage is found when ethene contaminated hydrogen is fed to a fuel cell running on hydrogen and oxygen at a constant load at 80°C and at highly humidified conditions.

  • 48. Lampinen, Markku J.
    et al.
    Kiros, Yohannes
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Spets, Jukka-Pekka
    Anttila, Tomi
    Research on bioorganic fuels as power sources2010In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 35, no 22, p. 12635-12641Article in journal (Refereed)
    Abstract [en]

    This paper deals with the kind of the bioorganic fuel cells that are equipped with or without ion exchange membranes The bioorganic materials of interest are alcohols (methanol ethanol) and glucose which are obtained from renewable energy sources such as biomass The operation temperatures of the direct fuel cells cover from room temperature up to 150 C The direct bioorganic fuel cells belong to the subject area of Advanced fuel cells of the Working group 4 in the EU COST Action 543 among the collaborating Universities and Institutes Bioorganic fuel cells are suitable for application in small portable power sources such as backups battery chargers and in electronic devices A number of current and earlier works are summansed and advances are highlighted in this area with special emphasis on glucose as a fuel.

  • 49. Lapa, C. M.
    et al.
    Figueiredo, F. M. L.
    de Souza, D. P. F.
    Song, L.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Marques, F. M. B.
    Synthesis and characterization of composite electrolytes based on samaria-doped ceria and Na/Li carbonates2010In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 35, no 7, p. 2953-2957Article in journal (Refereed)
    Abstract [en]

    Samaria-doped ceria-based composites with a 2:1 addition of Li and Na carbonates (or simple Na carbonate as admixture) were prepared mixing nanosized powders of the ceramic phase with the remaining constituents. Samples fired at relatively low temperatures (below 700 degrees C) were characterized by X-ray diffraction, scanning electron microscopy combined with energy dispersive spectroscopy and impedance spectroscopy in air. These composites showed a complex but homogeneous distribution of both phases, with one ceramic skeleton of bonded nanosized grains surrounded by the carbonate-based phase. Impedance spectroscopy data was used to confirm the impressive electrical conductivity of these materials, but also to put into evidence the complex nature of the charge transport process, clearly deviating from classical electrolytes.

  • 50.
    Larsson, Mårten
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Mosheni, Farzad
    Sweco, Sweden.
    Wallmark, Cecilia
    Sweco, Sweden.
    Grönkvist, Stefan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Alvfors, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Energy system analysis of the implications of hydrogen fuel cell vehicles in the Swedish road transport system2015In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 40, no 35, p. 11722-11729Article in journal (Refereed)
    Abstract [en]

    The focus on pathways to reduce the use of fossil fuels in the transport sector is intense in many countries worldwide. Considering that biofuels have a limited technical production potential and that battery electric vehicles suffer from technical limitations that put constraints on their general use in the transport sector, hydrogen-fuelled fuel cell vehicles may become a feasible alternative. Introduction of hydrogen in the transport sector will also transform the energy sector and create new interactions. The aim of this paper is to analyse the consequences and feasibility of such an integration in Sweden. Different pathways for hydrogen, electricity and methane to the transport sector are compared with regard to system energy efficiency. The well-to-wheel energy efficiencies for hydrogen and electricity are used for estimating the energy resources needed for hydrogen production and electric vehicles for a future Swedish transport sector based on renewable fuels. The analysis reveal that the well-to-wheel system efficiencies for hydrogen fuel cell vehicles are comparable to those of methane gas vehicles, even when biomethane is the energy source. The results further indicate that an increased hydrogen demand may have a less than expected impact on the primary energy supply in Sweden.

123 1 - 50 of 120
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf