Change search
Link to record
Permanent link

Direct link
BETA
Publications (2 of 2) Show all publications
Al-Soubaihi, R., Saoud, K. M., Fei, Y., Zar Myint, M. T., Saeed, S. & Dutta, J. (2020). Synthesis of hierarchically porous silica aerogel supported Palladium catalyst for low-temperature CO oxidation under ignition/extinction conditions. Microporous and Mesoporous Materials, 292, Article ID 109758.
Open this publication in new window or tab >>Synthesis of hierarchically porous silica aerogel supported Palladium catalyst for low-temperature CO oxidation under ignition/extinction conditions
Show others...
2020 (English)In: Microporous and Mesoporous Materials, ISSN 1387-1811, E-ISSN 1873-3093, Vol. 292, article id 109758Article in journal (Refereed) Published
Abstract [en]

Synthesis of well-dispersed palladium nanoparticles within silica aerogel pores with controlled size was carried out using sol-gel synthesis under supercritical ethanol drying. The high concentration of silanol groups on silica (SiO2) surface facilitated a superior palladium (Pd) loading up to 10 wt %. The synthesized Pd/SiO2 nanocomposite aerogels were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopic methods. The silica aerogel supported catalysts were found to have a wide pore size distribution. TEM investigations confirmed that Pd nanocrystals were located within the SiO2 microspores and mesopores. The catalyst was evaluated for carbon monoxide (CO) oxidation reaction under ignition/extinction conditions. The synthesized catalyst demonstrated a high catalytic activity at low operating temperatures (<200 °C) compared to unsupported Pd nanoparticles or bare SiO2 aerogels. This enhancement in CO oxidation activity with Pd/SiO2 aerogel catalysts are attributed to the small Pd particles, Pd interaction with the surface of the underlying SiO2 and the better dispersion of Pd particles within the SiO2 pores. Porosity played a more important role during the extinction cycle as a result of the slow dissipation of the heat leading to hysteresis. We demonstrate the influence of porosity of catalyst supports on the size, dispersion, and catalytic activity of Pd nanoparticles.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Vapor-Phase Synthesis, Carbon-Monoxide, Nanoparticle Catalysts, Pd/Sio2 Catalysts, Methane, Pd, Behavior, Oxygen, Reduction, Kinetics
National Category
Nano Technology Other Physics Topics
Research subject
Physics, Material and Nano Physics
Identifiers
urn:nbn:se:kth:diva-263430 (URN)10.1016/j.micromeso.2019.109758 (DOI)000498292200033 ()2-s2.0-85072675475 (Scopus ID)
Note

QC 20191205

Available from: 2019-12-05 Created: 2019-12-05 Last updated: 2019-12-20Bibliographically approved
Al-Soubaihi, R., Furesi, G., Saoud, K. M., Al-Muhtaseb, S. A., Khatat, A. E., Delogu, L. G. & Dutta, J. (2018). Silica and carbon decorated silica nanosheet impact on primary human immune cells. Colloids and Surfaces B: Biointerfaces, 172, 779-789
Open this publication in new window or tab >>Silica and carbon decorated silica nanosheet impact on primary human immune cells
Show others...
2018 (English)In: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 172, p. 779-789Article in journal (Refereed) Published
Abstract [en]

Silica nanosheets (SiO 2 NS) are considered to be a promising material in clinical practice for diagnosis and therapy applications. However, an appropriate surface functionalization is essential to guarantee high biocompatibility and molecule loading ability. Although SiO 2 NS are chemically stable, its effects on immune systems are still being explored. In this work, we successfully synthesized a novel 2D multilayer SiO 2 NS and SiO 2 NS coated with carbon (C/SiO 2 NS), and evaluated their impact on human Peripheral Blood Mononuclear Cells (PBMCs) and some immune cell subpopulations. We demonstrated that the immune response is strongly dependent on the surface functionalities of the SiO 2 NS. Ex vivo experiments showed an increase in biocompatibility of C/SiO 2 NS compared to SiO 2 NS, resulting in a lowering of hemoglobin release together with a reduction in cellular toxicity and cellular activation. However, none of them are directly involved in the activation of the acute inflammation process with a consequent release of pro-inflammatory cytokines. The obtained results provide an important direction towards the biomedical applications of silica nanosheets, rendering them an attractive material for the development of future immunological therapies.

Place, publisher, year, edition, pages
Elsevier B.V., 2018
Keywords
2D materials, Apoptosis assay, Bio compatibility, Carbon coated SiO 2, Cell toxicity, Cell viability, Characterization, Hemolysis tests, Immune cell, Layered silica, Nano-sheets, Secretion assay, Silica, Synthesis, Tumor necrosis factor alpha (TNFα), Biocompatibility, Carbon, Cell death, Chemical activation, Coated materials, Diagnosis, Immune system, Medical applications, Nanosheets, Synthesis (chemical), Toxicity, Apoptosis assays, Carbon-coated, Hemolysis test, Immune cells, Tumor necrosis factor alpha, carbon coated silica nanosheet, cytokine, hemoglobin, mulitlayer silica nanosheet, nanosheet, tumor necrosis factor, unclassified drug, adult, Article, cell activation, cell subpopulation, coated particle, controlled study, cytotoxicity, ex vivo study, hemoglobin synthesis, hemolysis assay, human, human cell, immune response, immunocompetent cell, inflammation, material coating, peripheral blood mononuclear cell, porosity, priority journal, protein secretion, structure analysis, surface area, surface property
National Category
Medical Biotechnology
Identifiers
urn:nbn:se:kth:diva-247029 (URN)10.1016/j.colsurfb.2018.09.022 (DOI)000455858500092 ()2-s2.0-85053867225 (Scopus ID)
Note

QC 20190626

Available from: 2019-06-26 Created: 2019-06-26 Last updated: 2019-06-26Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0589-6833

Search in DiVA

Show all publications