The Experts below are selected from a list of 2955 Experts worldwide ranked by ideXlab platform
Cordelia Selomulya - One of the best experts on this subject based on the ideXlab platform.
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Activity and Pyrophoricity of copper- and platinum-based catalysts for the water-gas-shift reaction
2011Co-Authors: Rothman Kam, Jason Scott, Cordelia Selomulya, Rose AmalAbstract:In this work the influence of support on LT-WGS activity by Cu-based catalysts was investigated. Of the metal oxides considered (ZnO, MgO, TiO2, Al2O3, SnO2), ZnO provided the best performance, with the results indicating the strength of CO chemisorption on the catalyst surface could be a factor contributing to activity. Pyrophoricity, or vulnerability to oxidative sintering, of Cu/ZnO during oxidative cycling was also investigated with this material exhibiting a highly pyrophoric nature, leading to severe sintering of the bulk and metallic phases of the catalyst and facilitating deactivation during the LT-WGSprocess. The Pyrophoricity of selected Pt-loaded metal oxides (TiO2, ZrO2, CeO2) was also examined and contrasted with that of Cu/ZnO. Despite no evidence of Pyrophoricity for any of the Pt-based catalysts, Pt sintering was still observed on the TiO2 and ZrO2 supports, accompanied by catalyst deactivation. Only Pt/CeO2 maintained its LT-WGS activity and metallic dispersion, with this attributed to the bonding strength between Pt deposits and the CeO2 surface.
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Pyrophoricity and stability of copper and platinum based water gas shift catalysts during oxidative shut down start up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
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Pyrophoricity and stability of copper and platinum based water-gas shift catalysts during oxidative shut-down/start-up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
Rothman Kam - One of the best experts on this subject based on the ideXlab platform.
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Activity and Pyrophoricity of copper- and platinum-based catalysts for the water-gas-shift reaction
2011Co-Authors: Rothman Kam, Jason Scott, Cordelia Selomulya, Rose AmalAbstract:In this work the influence of support on LT-WGS activity by Cu-based catalysts was investigated. Of the metal oxides considered (ZnO, MgO, TiO2, Al2O3, SnO2), ZnO provided the best performance, with the results indicating the strength of CO chemisorption on the catalyst surface could be a factor contributing to activity. Pyrophoricity, or vulnerability to oxidative sintering, of Cu/ZnO during oxidative cycling was also investigated with this material exhibiting a highly pyrophoric nature, leading to severe sintering of the bulk and metallic phases of the catalyst and facilitating deactivation during the LT-WGSprocess. The Pyrophoricity of selected Pt-loaded metal oxides (TiO2, ZrO2, CeO2) was also examined and contrasted with that of Cu/ZnO. Despite no evidence of Pyrophoricity for any of the Pt-based catalysts, Pt sintering was still observed on the TiO2 and ZrO2 supports, accompanied by catalyst deactivation. Only Pt/CeO2 maintained its LT-WGS activity and metallic dispersion, with this attributed to the bonding strength between Pt deposits and the CeO2 surface.
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Pyrophoricity and stability of copper and platinum based water gas shift catalysts during oxidative shut down start up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
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Pyrophoricity and stability of copper and platinum based water-gas shift catalysts during oxidative shut-down/start-up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
Christian Chatillon - One of the best experts on this subject based on the ideXlab platform.
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Experimental study of uranium carbide Pyrophoricity
Powder Technology, 2015Co-Authors: Clément Berthinier, S. Coullomb, C. Rado, Raphael Boichot, Elisabeth Blanquet, Christian ChatillonAbstract:Mixed plutonium and uranium monocarbide (UPuC) is considered as a possible fuel material for future nuclear gas fast reactors. Its safe handling is currently a major concern, because inflammation of this material under the shape of fine powders is easy and highly exothermic (Pyrophoricity) even under ambient temperature and partial pressure of oxygen inferior to 0.2 bar. CEA Marcoule is implied in both experimental and numerical studies on the UC powder oxidation exothermic reaction. Experimental tests consist in determining the influence of various parameters (gas composition, heating ramp, specific surface of powders) on the sample inflammation temperature. Two kinds of analytical apparatus are used: The differential thermal analysis (DTA) and the differential scanning calorimetry (DSC) coupled to the thermo gravimetric analysis (TGA). These apparatus are also linked to a gas mass spectrometer to follow the composition of combustion chamber gases. Results obtained with small quantities revealed that UC powder is highly reactive in air in the temperature range of 150-250 degrees C and showed a strong dependence between powder height in crucibles and inflammation temperature.
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experimental study of uranium carbide Pyrophoricity
Powder Technology, 2011Co-Authors: Clément Berthinier, S. Coullomb, C. Rado, Raphael Boichot, Elisabeth Blanquet, Christian ChatillonAbstract:Abstract Mixed plutonium and uranium monocarbide (UPuC) is considered as a possible fuel material for future nuclear gas fast reactors. Its safe handling is currently a major concern, because inflammation of this material under the shape of fine powders is easy and highly exothermic (Pyrophoricity) even under ambient temperature and partial pressure of oxygen inferior to 0.2 bar. CEA Marcoule is implied in both experimental and numerical studies on the UC powder oxidation exothermic reaction. Experimental tests consist in determining the influence of various parameters (gas composition, heating ramp, specific surface of powders) on the sample inflammation temperature. Two kinds of analytical apparatus are used: The differential thermal analysis (DTA) and the differential scanning calorimetry (DSC) coupled to the thermo gravimetric analysis (TGA). These apparatus are also linked to a gas mass spectrometer to follow the composition of combustion chamber gases. Results obtained with small quantities revealed that UC powder is highly reactive in air in the temperature range of 150–250 °C and showed a strong dependence between powder height in crucibles and inflammation temperature.
Rose Amal - One of the best experts on this subject based on the ideXlab platform.
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Activity and Pyrophoricity of copper- and platinum-based catalysts for the water-gas-shift reaction
2011Co-Authors: Rothman Kam, Jason Scott, Cordelia Selomulya, Rose AmalAbstract:In this work the influence of support on LT-WGS activity by Cu-based catalysts was investigated. Of the metal oxides considered (ZnO, MgO, TiO2, Al2O3, SnO2), ZnO provided the best performance, with the results indicating the strength of CO chemisorption on the catalyst surface could be a factor contributing to activity. Pyrophoricity, or vulnerability to oxidative sintering, of Cu/ZnO during oxidative cycling was also investigated with this material exhibiting a highly pyrophoric nature, leading to severe sintering of the bulk and metallic phases of the catalyst and facilitating deactivation during the LT-WGSprocess. The Pyrophoricity of selected Pt-loaded metal oxides (TiO2, ZrO2, CeO2) was also examined and contrasted with that of Cu/ZnO. Despite no evidence of Pyrophoricity for any of the Pt-based catalysts, Pt sintering was still observed on the TiO2 and ZrO2 supports, accompanied by catalyst deactivation. Only Pt/CeO2 maintained its LT-WGS activity and metallic dispersion, with this attributed to the bonding strength between Pt deposits and the CeO2 surface.
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Pyrophoricity and stability of copper and platinum based water gas shift catalysts during oxidative shut down start up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
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Pyrophoricity and stability of copper and platinum based water-gas shift catalysts during oxidative shut-down/start-up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
Jason Scott - One of the best experts on this subject based on the ideXlab platform.
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Activity and Pyrophoricity of copper- and platinum-based catalysts for the water-gas-shift reaction
2011Co-Authors: Rothman Kam, Jason Scott, Cordelia Selomulya, Rose AmalAbstract:In this work the influence of support on LT-WGS activity by Cu-based catalysts was investigated. Of the metal oxides considered (ZnO, MgO, TiO2, Al2O3, SnO2), ZnO provided the best performance, with the results indicating the strength of CO chemisorption on the catalyst surface could be a factor contributing to activity. Pyrophoricity, or vulnerability to oxidative sintering, of Cu/ZnO during oxidative cycling was also investigated with this material exhibiting a highly pyrophoric nature, leading to severe sintering of the bulk and metallic phases of the catalyst and facilitating deactivation during the LT-WGSprocess. The Pyrophoricity of selected Pt-loaded metal oxides (TiO2, ZrO2, CeO2) was also examined and contrasted with that of Cu/ZnO. Despite no evidence of Pyrophoricity for any of the Pt-based catalysts, Pt sintering was still observed on the TiO2 and ZrO2 supports, accompanied by catalyst deactivation. Only Pt/CeO2 maintained its LT-WGS activity and metallic dispersion, with this attributed to the bonding strength between Pt deposits and the CeO2 surface.
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Pyrophoricity and stability of copper and platinum based water gas shift catalysts during oxidative shut down start up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
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Pyrophoricity and stability of copper and platinum based water-gas shift catalysts during oxidative shut-down/start-up operation
Chemical Engineering Science, 2010Co-Authors: Rothman Kam, Jason Scott, Rose Amal, Cordelia SelomulyaAbstract:Abstract The Pyrophoricity of Cu/ZnO-based and Pt-based catalysts was studied during oxidative shut-down/start-up of the low-temperature water-gas shift (LT-WGS) reaction to assess whether these catalysts are suitable for fuel cell application. The Cu/ZnO-based catalysts were observed to display high levels of Pyrophoricity manifested as a sharp temperature rise of the catalyst bed upon air introduction. This promoted severe sintering of the bulk and metallic phases of the catalyst facilitating catalyst deactivation. No Pyrophoricity was observed for any of the Pt-based catalysts; however, sintering of the metallic phase in Pt/TiO 2 and Pt/ZrO 2 persisted, leading to a decrease in activity. It was likely that the sintering of Pt occurred during LT-WGS operation itself. In contrast, Pt/CeO 2 was the only catalyst which retained its activity, displaying no loss in specific surface area or metal dispersion throughout the entire process making it the most suitable candidate of the materials investigated for fuel cell systems. Temperature-programmed oxidation studies indicated deactivation by the oxidative shut-down/start-up operation did not result from the build-up of carbonaceous species.
