Conference Presentations by Dr. Ashish Kumar
Cerium oxide (CeO2) acts as an effective heterogeneous catalyst for the transamidation reaction o... more Cerium oxide (CeO2) acts as an effective heterogeneous catalyst for the transamidation reaction of amides with amines. The CeO2 was prepared by hydrothermal methods using different cerium precursor such as cerium (III) chloride heptahydrate [CeCl3*7H2O], cerium nitrate hexahydrate [Ce(NO3)3*6H2O], ceric ammonium nitrate [(NH4)2Ce(NO3)6] and cerium (III) acetate [Ce(C2H3O2)3*1.5H2O]. These catalysts have shown highest catalytic activity for transamidation of acetamide with N-octylamine under solvent free conditions.
Papers by Dr. Ashish Kumar
A series of catalysts with different Ru contents supported on MCM-41 were prepared by micro-emuls... more A series of catalysts with different Ru contents supported on MCM-41 were prepared by micro-emulsion (ME) method. These catalysts were characterized by X-ray diffraction, BET-surface area,H2-temperature programmed reduction, pore size distribution, XPS, transmission electron microscopy,and CO-chemisorption measurements. The catalytic properties of Ru/MCM-41 catalysts were evaluatedduring the vapor phase hydrogenolysis of glycerol on various reaction parameters. The catalysts haveshown an unprecedented activity for the complete hydrogenolysis of glycerol at moderate reaction tem-perature under normal atmospheric pressure. The nanostructured ruthenium deposited on MCM-41support plays a significant role in improving the catalytic activity and its stability. The glycerol conver-sion and the selectivity of 1,2propanediol (1,2-PD), 1,3-propanediol (1,3-PD) and various products weremainly depend on the method of catalyst preparation, effect of support and also on the Ru loading.
The vapor phase oxidation of benzyl alcohol was investigated over gold nanoparticles supported on... more The vapor phase oxidation of benzyl alcohol was investigated over gold nanoparticles supported on mesoporous titanium dioxide (anatase) catalysts under aerobic conditions. The catalysts were prepared by homogeneous
deposition–precipitation method using urea as the precipitating agent. The physico-chemical properties of the synthesized catalysts were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), pore size distribution (PSD), CO-chemisorption and X-ray photoelectron spectroscopy (XPS) techniques. The crystallite size of gold in Au/TiO2 catalysts was measured from XRD. The mesoporosity of TiO2 support and Au/TiO2 catalysts were confirmed by PSD analysis. TEM results suggest that gold nanoparticles are well dispersed over mesoporous TiO2. The catalytic functionality is well substantiated
with particle size measured from TEM. XPS results reveal the formation of Au(0) after chemical reduction by NaBH4. The vapor phase benzyl alcohol oxidation was used as a test reaction to investigate the influence of the metal, nature of the support, and of metalsupport interactions in Au/TiO2 catalysts and also the
catalytic activity and stability of the Au/TiO2 catalysts. The conversion of benzyl alcohol was found to increase with decrease in the size of gold particles. Smaller gold particles and a higher amount of small gold particles had a beneficial
effect on the catalytic activity. The catalytic activity in the presence of oxygen is believed to be associated with the transport of electrons through the catalyst to the adsorbed oxygen on the surface.
Gold nanoparticles supported on SBA-15 are prepared by homogenous deposition-precipitation method... more Gold nanoparticles supported on SBA-15 are prepared by homogenous deposition-precipitation method (HDP) using urea as the precipitating agent. The structural features of the synthesized catalysts were characterized by various techniques such as X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption–desorption (BET), pore size distribution (PSD), CO
chemisorption and X-ray photoelectron spectroscopy (XPS). The catalytic activity and stability of the Au/SBA-15 catalysts are investigated during the vapor phase aerobic oxidation of benzyl alcohol. The BJH pore size distribution results of SBA-15 support and Au/SBA-15 catalysts reveals that the formation of mesoporous structure in all the samples. TEM results suggest that Au nanoparticles are highly dispersed over SBA-15 and long range order of hexagonal mesopores of SBA-15 is well retained even after the deposition of Au metallic nanoparticles. XPS study reveals the formation of Au (0) after chemical reduction by NaBH4. The particle size measured from CO-chemisorption and TEM analysis are well correlated with the TOF values of the reaction. Au/SBA-15 catalysts are found to show higher activity compare to Au/TiO2 and Au/MgO catalysts during the vapor phase oxidation
of benzyl alcohol. The catalytic functionality are well substantiated with particle size measured from TEM. The crystallite size of Au in both fresh and spent catalysts were measured from X-ray diffraction.
Uploads
Conference Presentations by Dr. Ashish Kumar
Papers by Dr. Ashish Kumar
deposition–precipitation method using urea as the precipitating agent. The physico-chemical properties of the synthesized catalysts were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), pore size distribution (PSD), CO-chemisorption and X-ray photoelectron spectroscopy (XPS) techniques. The crystallite size of gold in Au/TiO2 catalysts was measured from XRD. The mesoporosity of TiO2 support and Au/TiO2 catalysts were confirmed by PSD analysis. TEM results suggest that gold nanoparticles are well dispersed over mesoporous TiO2. The catalytic functionality is well substantiated
with particle size measured from TEM. XPS results reveal the formation of Au(0) after chemical reduction by NaBH4. The vapor phase benzyl alcohol oxidation was used as a test reaction to investigate the influence of the metal, nature of the support, and of metalsupport interactions in Au/TiO2 catalysts and also the
catalytic activity and stability of the Au/TiO2 catalysts. The conversion of benzyl alcohol was found to increase with decrease in the size of gold particles. Smaller gold particles and a higher amount of small gold particles had a beneficial
effect on the catalytic activity. The catalytic activity in the presence of oxygen is believed to be associated with the transport of electrons through the catalyst to the adsorbed oxygen on the surface.
chemisorption and X-ray photoelectron spectroscopy (XPS). The catalytic activity and stability of the Au/SBA-15 catalysts are investigated during the vapor phase aerobic oxidation of benzyl alcohol. The BJH pore size distribution results of SBA-15 support and Au/SBA-15 catalysts reveals that the formation of mesoporous structure in all the samples. TEM results suggest that Au nanoparticles are highly dispersed over SBA-15 and long range order of hexagonal mesopores of SBA-15 is well retained even after the deposition of Au metallic nanoparticles. XPS study reveals the formation of Au (0) after chemical reduction by NaBH4. The particle size measured from CO-chemisorption and TEM analysis are well correlated with the TOF values of the reaction. Au/SBA-15 catalysts are found to show higher activity compare to Au/TiO2 and Au/MgO catalysts during the vapor phase oxidation
of benzyl alcohol. The catalytic functionality are well substantiated with particle size measured from TEM. The crystallite size of Au in both fresh and spent catalysts were measured from X-ray diffraction.
deposition–precipitation method using urea as the precipitating agent. The physico-chemical properties of the synthesized catalysts were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), pore size distribution (PSD), CO-chemisorption and X-ray photoelectron spectroscopy (XPS) techniques. The crystallite size of gold in Au/TiO2 catalysts was measured from XRD. The mesoporosity of TiO2 support and Au/TiO2 catalysts were confirmed by PSD analysis. TEM results suggest that gold nanoparticles are well dispersed over mesoporous TiO2. The catalytic functionality is well substantiated
with particle size measured from TEM. XPS results reveal the formation of Au(0) after chemical reduction by NaBH4. The vapor phase benzyl alcohol oxidation was used as a test reaction to investigate the influence of the metal, nature of the support, and of metalsupport interactions in Au/TiO2 catalysts and also the
catalytic activity and stability of the Au/TiO2 catalysts. The conversion of benzyl alcohol was found to increase with decrease in the size of gold particles. Smaller gold particles and a higher amount of small gold particles had a beneficial
effect on the catalytic activity. The catalytic activity in the presence of oxygen is believed to be associated with the transport of electrons through the catalyst to the adsorbed oxygen on the surface.
chemisorption and X-ray photoelectron spectroscopy (XPS). The catalytic activity and stability of the Au/SBA-15 catalysts are investigated during the vapor phase aerobic oxidation of benzyl alcohol. The BJH pore size distribution results of SBA-15 support and Au/SBA-15 catalysts reveals that the formation of mesoporous structure in all the samples. TEM results suggest that Au nanoparticles are highly dispersed over SBA-15 and long range order of hexagonal mesopores of SBA-15 is well retained even after the deposition of Au metallic nanoparticles. XPS study reveals the formation of Au (0) after chemical reduction by NaBH4. The particle size measured from CO-chemisorption and TEM analysis are well correlated with the TOF values of the reaction. Au/SBA-15 catalysts are found to show higher activity compare to Au/TiO2 and Au/MgO catalysts during the vapor phase oxidation
of benzyl alcohol. The catalytic functionality are well substantiated with particle size measured from TEM. The crystallite size of Au in both fresh and spent catalysts were measured from X-ray diffraction.