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Weissenrieder, JonasORCID iD iconorcid.org/0000-0003-1631-4293
Publications (10 of 69) Show all publications
Marks, K., Besharat, Z., Soldemo, M., Önsten, A., Weissenrieder, J., Stenlid, J. H., . . . Göthelid, M. (2019). Adsorption and Decomposition of Ethanol on Cu2O(111) and (100). JOURNAL OF PHYSICAL CHEMISTRY C, 123(33), 20384-20392
Open this publication in new window or tab >>Adsorption and Decomposition of Ethanol on Cu2O(111) and (100)
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2019 (English)In: JOURNAL OF PHYSICAL CHEMISTRY C, Vol. 123, no 33, p. 20384-20392Article in journal (Refereed) Published
Abstract [en]

Ethanol dehydrogenation on metal oxides such as Cu2O is an important reaction for the production of renewable energy by fuel cells both via the production of H-2 fuel and via application in direct alcohol fuel cells. To better understand this reaction, we studied the adsorption, dissociation, and desorption of ethanol on Cu2O(111) and (100) surfaces using high-resolution photoelectron spectroscopy, vibrational sum-frequency generation spectroscopy, and temperature-programmed desorption accompanied by density functional theory calculations. On Cu-2(100), the first layer consists primarily of dissociatively adsorbed ethoxy. Second and third layers of ethanol physisorb at low temperatures and desorb below 200 K. On the Cu2O(111) surface, adsorption is mixed as ethoxy, ethanol, and the products following C-C cleavage, CHx, and OCHx, are found in the first layer. Upon heating, products following both C-C and C-O bond breaking are observed on both surfaces and continued heating accentuates molecular cracking. C-O cleavage occurs more on the (100) surface, whereas on the Cu2O(111) surface, C-C cleavage dominates and occurs at lower temperatures than those for the (100) surface. The increased ability of Cu2O(111) to crack ethanol is explained by the varied surface structure including surface oxygen, electron-rich O vacancies, and Cu.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-259447 (URN)10.1021/acs.jpcc.9b05394 (DOI)000482545700035 ()2-s2.0-85071416412 (Scopus ID)
Note

QC 20190923

Available from: 2019-09-23 Created: 2019-09-23 Last updated: 2019-09-23Bibliographically approved
Cao, L., Liu, W., Luo, Q., Yin, R., Wang, B., Weissenrieder, J., . . . Lu, J. (2019). Atomically dispersed iron hydroxide anchored on Pt for preferential oxidation of CO in H-2. Nature, 565(7741), 631-635
Open this publication in new window or tab >>Atomically dispersed iron hydroxide anchored on Pt for preferential oxidation of CO in H-2
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2019 (English)In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 565, no 7741, p. 631-635Article in journal (Refereed) Published
Abstract [en]

Proton-exchange-membrane fuel cells (PEMFCs) are attractive next-generation power sources for use in vehicles and other applications(1), with development efforts focusing on improving the catalyst system of the fuel cell. One problem is catalyst poisoning by impurity gases such as carbon monoxide (CO), which typically comprises about one per cent of hydrogen fuel(2-4). A possible solution is on-board hydrogen purification, which involves preferential oxidation of CO in hydrogen (PROX)(3-7). However, this approach is challenging(8-15) because the catalyst needs to be active and selective towards CO oxidation over a broad range of low temperatures so that CO is efficiently removed (to below 50 parts per million) during continuous PEMFC operation (at about 353 kelvin) and, in the case of automotive fuel cells, during frequent cold-start periods. Here we show that atomically dispersed iron hydroxide, selectively deposited on silica-supported platinum (Pt) nanoparticles, enables complete and 100 per cent selective CO removal through the PROX reaction over the broad temperature range of 198 to 380 kelvin. We find that the mass-specific activity of this system is about 30 times higher than that of more conventional catalysts consisting of Pt on iron oxide supports. In situ X-ray absorption fine-structure measurements reveal that most of the iron hydroxide exists as Fe-1(OH)(x) clusters anchored on the Pt nanoparticles, with density functional theory calculations indicating that Fe-1(OH)(x)-Pt single interfacial sites can readily react with CO and facilitate oxygen activation. These findings suggest that in addition to strategies that target oxide-supported precious-metal nanoparticles or isolated metal atoms, the deposition of isolated transition-metal complexes offers new ways of designing highly active metal catalysts.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2019
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-244110 (URN)10.1038/s41586-018-0869-5 (DOI)000457404000045 ()30700869 (PubMedID)2-s2.0-85060888174 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation, 2012.0321Swedish Research Council, 2015-04062
Note

QC 20190219

Available from: 2019-02-19 Created: 2019-02-19 Last updated: 2019-02-19Bibliographically approved
Soldemo, M., Vandichel, M., Gronbeck, H. & Weissenrieder, J. (2019). Initial Fe3O4(100) Formation on Fe(100). The Journal of Physical Chemistry C, 123(26), 16317-16325
Open this publication in new window or tab >>Initial Fe3O4(100) Formation on Fe(100)
2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 26, p. 16317-16325Article in journal (Refereed) Published
Abstract [en]

The initial oxidation of Fe(100) at 400 degrees C has been studied by X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and low-energy electron diffraction, in combination with density functional theory calculations. The first observed well-ordered surface oxide is formed at a coverage of similar to 3 oxygen atoms per unreconstructed surface Fe(100) atom. STM shows that this surface oxide is terminated by straight atomic rows exhibiting a p(2 X 1) periodicity. However, already for oxide films with a coverage of similar to 4 oxygen atoms (corresponding to one Fe3O4 unit cell thickness), wiggly atomic rows appear similar to the c(2 X 2) reconstructed Fe3O4 (100)-surface with the Fe3O4 unit vectors rotated 45 degrees to Fe(100). The wiggly rows are a consequence of subsurface cation iron vacancies, which previously have been observed for bulk surfaces. The formation of subsurface vacancies is supported by the XPS O is signature, which is modeled by considering the core-level shifts for all oxygen atoms in the film. Throughout the oxidation series, the microscopy results reveal a layer-by-layer (Frank-van der Merwe) growth.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-255382 (URN)10.1021/acs.jpcc.9b04625 (DOI)000474796600046 ()2-s2.0-85070253694 (Scopus ID)
Note

QC 20190730

Available from: 2019-07-30 Created: 2019-07-30 Last updated: 2019-10-04Bibliographically approved
Tissot, H., Wang, C., Stenlid, J. H., Panahi, M., Kaya, S., Soldemo, M., . . . Weissenrieder, J. (2019). Interaction of Atomic Hydrogen with the Cu2O(100) and (111) Surfaces. The Journal of Physical Chemistry C, 123(36), 22172-22180
Open this publication in new window or tab >>Interaction of Atomic Hydrogen with the Cu2O(100) and (111) Surfaces
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2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 36, p. 22172-22180Article in journal (Refereed) Published
Abstract [en]

Reduction of Cu2O by hydrogen is a common preparation step for heterogeneous catalysts; however, a detailed understanding of the atomic reaction pathways is still lacking. Here, we investigate the interaction of atomic hydrogen with the Cu2O(100):(3,0;1,1) and Cu2O(111):(root 3 x root 3)R30 degrees surfaces using scanning tunneling microscopy (STM), low-energy electron diffraction, temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). The experimental results are compared to density functional theory simulations. At 300 K, we identify the most favorable adsorption site on the Cu2O(100) surface: hydrogen atoms bind to an oxygen site located at the base of the atomic rows intrinsic to the (3,0;1,1) surface. The resulting hydroxyl group subsequently migrates to a nearby Cu trimer site. TPD analysis identifies H-2 as the principal desorption product. These observations imply that H-2 is formed through a disproportionation reaction of surface hydroxyl groups. The interaction of H with the (111) surface is more complex, including coordination to both Cu+ and O-CUS sites. STM and XPS analyses reveal the formation of metallic copper clusters on the Cu2O surfaces after cycles of hydrogen exposure and annealing. The interaction of the Cu clusters with the substrate is notably different for the two surface terminations studied: after annealing, the Cu clusters coalesce on the (100) termination, and the (3,0;1,1) reconstruction is partially recovered. Clusters formed on the (111) surface are less prone to coalescence, and the (root 3 x root 3)R30 degrees reconstruction was not recovered by heat treatment, indicating a weaker Cu cluster to support interaction on the (100) surface.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-261961 (URN)10.1021/acs.jpcc.9b03888 (DOI)000486360900036 ()2-s2.0-85072714617 (Scopus ID)
Note

QC 20191015

Available from: 2019-10-15 Created: 2019-10-15 Last updated: 2019-10-15Bibliographically approved
Tissot, H., Wang, C., Sterdid, J. H., Brinck, T. & Weissenrieder, J. (2019). The Surface Structure of Cu2O(100): Nature of Defects. The Journal of Physical Chemistry C, 123(13), 7696-7704
Open this publication in new window or tab >>The Surface Structure of Cu2O(100): Nature of Defects
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2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 13, p. 7696-7704Article in journal (Refereed) Published
Abstract [en]

The Cu2O(100) surface is most favorably terminated by a (3,0;1,1) reconstruction under ultrahigh-vacuum conditions. As most oxide surfaces, it exhibit defects, and it is these sites that are focus of attention in this study. The surface defects are identified, their properties are investigated, and procedures to accurately control their coverage are demonstrated by a combination of scanning tunneling microscopy (STM) and simulations within the framework of density functional theory (DFT). The most prevalent surface defect was identified as an oxygen vacancy. By comparison of experimental results, formation energies, and simulated STM images, the location of the oxygen vacancies was identified as an oxygen vacancy in position B, located in the valley between the two rows of oxygen atoms terminating the unperturbed surface. The coverage of defects is influenced by the surface preparation parameters and the history of the sample. Furthermore, using low-energy electron beam bombardment, we show that the oxygen vacancy coverage can be accurately controlled and reach a complete surface coverage (1 per unit cell or 1.8 defects per nm(2)) without modification to the periodicity of the surface, highlighting the importance of using local probes when investigating oxide surfaces.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-251204 (URN)10.1021/acs.jpcc.8b05156 (DOI)000463844500019 ()2-s2.0-85050489968 (Scopus ID)
Note

QC 20190724

Available from: 2019-07-24 Created: 2019-07-24 Last updated: 2019-07-24Bibliographically approved
Wang, C., Tissot, H., Escudero, C., Perez-Dieste, V., Stacchiola, D. & Weissenrieder, J. (2018). Redox Properties of Cu2O(100) and (111) Surfaces. Paper presented at ENDENING WD, 1989, SURFACE SCIENCE, V216, P429 eda S, 1999, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, V1, P4485. The Journal of Physical Chemistry C, 122(50), 28684-28691
Open this publication in new window or tab >>Redox Properties of Cu2O(100) and (111) Surfaces
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2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 50, p. 28684-28691Article in journal (Refereed) Published
Abstract [en]

Intense research efforts are directed toward Cu and Cu2O based catalysts as they are viewed as potential replacements for noble metal catalysts. However, applications are hampered by deactivation, e.g., through facile complete oxidation to CuO. Despite the importance of the redox processes for Cu2O catalysts, a molecular level understanding of the deactivation process is still lacking. Here we study the initial stages of oxidization of well-defined Cu2O bulk single crystals of (100) and (111) termination by means of synchrotron radiation X-ray photoemission spectroscopy (XPS) and scanning tunneling microscopy (STM). Exposure of the (100) surface to 1 mbar O-2 at 25 degrees C results in the formation of a 1.0 monolayer (ML) CuO surface oxide. The surface is covered by 0.7 ML OH groups from trace moisture in the reaction gas. In contrast, neither hydroxylation nor oxidation was observed on the (111) surface under similar mild exposure conditions. On Cu2O(111) the initial formation of CuO requires annealing to similar to 400 degrees C in 1 mbar 02, highlighting the markedly different reactivity of the two Cu2O surfaces. Annealing of the (100) surface, under ultrahigh vacuum conditions, to temperatures up to similar to 225 degrees C resulted in removal of the OH groups (0.46 ML decrease) at a rate similar to a detected increase in CuO coverage (0.45 ML increase), suggesting the reaction path 2OH(adsorbed) + CU2Osolid -> H2Ogas + 2CuO(solid). STM was used to correlate the observed changes in surface chemistry with surface morphology, confirming the surface hydroxylation and CuO formation. The STM analysis showed dramatic changes in surface morphology demonstrating a high mobility of the active species under reaction conditions.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2018
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-241329 (URN)10.1021/acs.jpcc.8b08494 (DOI)000454566700024 ()2-s2.0-85058560424 (Scopus ID)
Conference
ENDENING WD, 1989, SURFACE SCIENCE, V216, P429 eda S, 1999, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, V1, P4485
Note

QC 20190123

Available from: 2019-01-23 Created: 2019-01-23 Last updated: 2019-05-17Bibliographically approved
Beaussant Törne, K. B., Khan, F. A., Ornberg, A. & Weissenrieder, J. (2018). Zn-Mg and Zn-Ag degradation mechanism under biologically relevant conditions. Surface Innovations, 6(1-2), 81-92
Open this publication in new window or tab >>Zn-Mg and Zn-Ag degradation mechanism under biologically relevant conditions
2018 (English)In: Surface Innovations, ISSN 2050-6252, E-ISSN 2050-6260, Vol. 6, no 1-2, p. 81-92Article in journal (Refereed) Published
Abstract [en]

Zinc (Zn) alloys form a promising new class of biodegradable metals that combine suitable mechanical properties with the favorable degradation properties of pure zinc. However, the current understanding of the influence of alloying elements on the corrosion of zinc alloys, in biologically relevant media, is limited. The authors studied the degradation of three alloys, zinc-4 wt% silver (Ag), zinc-0.5 wt% magnesium (Mg) and zinc-3 wt% magnesium by in situ electrochemical impedance spectroscopy (EIS). After exposure for 1 h or 30 d, the samples were characterized by infrared spectroscopy and scanning electron microscopy. The presence of secondary phases in the alloy microstructure induced selective corrosion and increased the degradation rate. EIS analysis revealed an increase in surface inhomogeneity already at short (hours) immersion times. The microgalvanic corrosion of the zinc-silver alloy resulted in enrichment of the AgZn3 phase at the sample surface. The enrichment of silver and potential release of AgZn3 particles may result in complications during the tissue regeneration. The zinc-magnesium alloy surface was depleted of the magnesium-rich phase after 8-12 d. The selective dissolution caused local precipitation of corrosion products and a thicker corrosion layer with larger pore size consistent with increased corrosion rate.

Place, publisher, year, edition, pages
ICE PUBLISHING, 2018
Keywords
alloys, biodegradable, surface characterization
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-221914 (URN)10.1680/jsuin.17.00053 (DOI)000419942800011 ()2-s2.0-85040649305 (Scopus ID)
Note

QC 20180201

Available from: 2018-02-01 Created: 2018-02-01 Last updated: 2018-02-01Bibliographically approved
Besharat, Z., Halldin Stenlid, J., Soldemo, M., Marks, K., Önsten, A., Johnson, M., . . . Göthelid, M. (2017). Dehydrogenation of methanol on Cu2O(100) and (111). Journal of Chemical Physics, 146(24)
Open this publication in new window or tab >>Dehydrogenation of methanol on Cu2O(100) and (111)
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2017 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 146, no 24Article in journal (Refereed) Published
Abstract [en]

Adsorption and desorption of methanol on the (111) and (100) surfaces of  Cu2O have been studied using high-resolution photoelectron spectroscopy in the temperature range 120–620 K, in combination with density functional theorycalculations and sum frequency generation spectroscopy. The bare (100) surfaceexhibits a (3,0; 1,1) reconstruction but restructures during the adsorption process into a Cu-dimer geometry stabilized by methoxy and hydrogen binding in Cu-bridge sites. During the restructuring process, oxygen atoms from the bulk that can host hydrogen appear on the surface. Heating transforms methoxy to formaldehyde, but further dehydrogenation is limited by the stability of the surface and the limited access to surface oxygen. The (√3 × √3)R30°-reconstructed (111) surface is based on ordered surface oxygen and copper ions and vacancies, which offers a palette of adsorption and reaction sites. Already at 140 K, a mixed layer of methoxy, formaldehyde, and CHxOy is formed. Heating to room temperature leaves OCH and CHx. Thus both CH-bond breaking and CO-scission are active on this  surface at low temperature. The higher ability to dehydrogenate methanol on (111) compared to (100) is explained by the multitude of adsorption sites and, in particular, the availability of surfaceoxygen.

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2017
National Category
Physical Chemistry
Identifiers
urn:nbn:se:kth:diva-211786 (URN)10.1063/1.4989472 (DOI)000404302600033 ()2-s2.0-85021446807 (Scopus ID)
Note

QC 20170816

Available from: 2017-08-13 Created: 2017-08-13 Last updated: 2017-11-10Bibliographically approved
Fashandi, H., Soldemo, M., Weissenrieder, J., Gothelid, M., Eriksson, J., Eklund, P., . . . Andersson, M. (2016). Applicability of MOS structures in monitoring catalytic properties, as exemplified for monolayer-iron-oxide-coated porous platinum films. Journal of Catalysis, 344, 583-590
Open this publication in new window or tab >>Applicability of MOS structures in monitoring catalytic properties, as exemplified for monolayer-iron-oxide-coated porous platinum films
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2016 (English)In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 344, p. 583-590Article in journal (Refereed) Published
Abstract [en]

Metal Oxide Semiconductor (MOS) capacitor devices comprised of monolayer iron oxide-coated as well as non-coated polycrystalline Pt deposited on oxidized silicon carbide substrates have been fabricated and their usefulness as realistic model systems in catalyst studies development was evaluated. The CO oxidation characteristics of both iron oxide- and non-coated Pt catalysts were investigated using mass spectrometry, monitoring the carbon dioxide production rate for different combinations of carbon monoxide (CO) and oxygen concentrations at various temperatures. Additionally, the output capacitance of the MOS model catalysts was recorded for each individual CO oxidation activity. A low-temperature shift in CO oxidation characteristics for the monolayer-coated compared to the non-coated Pt catalysts was observed, similar to that previously reported for monolayer iron oxide grown on single-crystalline Pt substrates. A strong correlation between the output capacitance of the MOS structures and the CO oxidation characteristics was found for both monolayer- and non-coated model catalysts. Furthermore, the devices exhibit retained MOS electrical output and CO oxidation characteristics as well as an unaffected catalyst surface composition, as confirmed by photoelectron spectroscopy, even after 200 h of continuous model catalyst operation. In addition to the implications on practical applicability of monolayer iron oxide coating on widely used polycrystalline Pt films in real-world catalysts and sensors, the findings also point to new possibilities regarding the use of MOS model systems for in situ characterization, high throughput screening, and tailoring of e.g. catalyst- and fuel-cell-electrode materials for specific applications.

Place, publisher, year, edition, pages
Academic Press, 2016
Keywords
Monolayer iron oxide, Platinum catalyst, Catalytic activity, CO oxidation, Field effect device, MOS capacitor, CO sensor
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-199751 (URN)10.1016/j.jcat.2016.10.018 (DOI)000390182800057 ()2-s2.0-84996565999 (Scopus ID)
Note

QC 20170123

Available from: 2017-01-23 Created: 2017-01-16 Last updated: 2017-06-28Bibliographically approved
Soldemo, M., Lundgren, E. & Weissenrieder, J. (2016). Oxidation of Fe(110) in oxygen gas at 400 °c. Surface Science, 644, 172-179
Open this publication in new window or tab >>Oxidation of Fe(110) in oxygen gas at 400 °c
2016 (English)In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 644, p. 172-179Article in journal (Refereed) Published
Abstract [en]

The initial oxidation of Fe(110) in oxygen gas at 400 °C beyond initial adsorbate structures has been studied using X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, low-energy electron diffraction, and scanning tunneling microscopy (STM). Formation of several ordered phases of surface oxides is observed at oxygen coverages between approximately 2.3 and 3.5 oxygen atoms/Fe(110) surface atom. Initially, a FeO(111)-like film is formed with a parallelogram-shaped moiré pattern. It has two mirror domains that are formed symmetrically around the growth direction of a zigzag-shaped adsorbate structure. With increased local oxygen coverage, the moiré structure transforms into a ball-shaped form. Both these moiré structures have equal atomic stacking at the surface and equal apparent height in STM, suggesting oxygen ions diffusing into the film upon oxidation and that the oxide growth takes place at the iron-iron oxide interface. The FeO(111)-like film turns into a Fe3O4(111)-like film with a triangular bistable surface termination as the oxidation proceeds further. The FeO(111)-like film growth proceeds according to the Frank-van der Merwe mechanism while the Fe3O4(111)-like film grows according to the Stranski-Krastanov mechanism.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Fe(110), Iron oxide thin film, Low-energy electron diffraction, Photoelectron spectroscopy, Scanning tunneling microscopy
National Category
Inorganic Chemistry Condensed Matter Physics
Identifiers
urn:nbn:se:kth:diva-180936 (URN)10.1016/j.susc.2015.10.058 (DOI)000367489000027 ()2-s2.0-84949494103 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation, Dnr 2012.0321Swedish Research Council, 621-2008-576
Note

QC 20160205

Available from: 2016-01-26 Created: 2016-01-25 Last updated: 2017-11-30Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1631-4293

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