The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influen...The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influenced by the morphology of the support.Hydrothermal synthesis was employed to produce different morphologies ofγ-Al_(2)O_(3):flower-likeγ-Al_(2)O_(3)(f)exposing(110)crystal faces,sheet-likeγ-Al_(2)O_(3)(s)revealing(100)crystal faces,and rod-likeγ-Al_(2)O_(3)(r)displaying(111)crystal faces,followed by loading PtCo nanoparticles.The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles,and an increase in the alloying degree correlates with enhanced catalyst reactivity.Pt_(3)Co intermetallic compounds were identified onγ-Al_(2)O_(3)(f)exposing(110)crystal faces,and PtCo/γ-Al_(2)O_(3)(f)showed high catalytic activity in the CO-PROX reaction,achieving 100%CO conversion across a broad temperature range of 50−225°C.In contrast,only partial alloying of PtCo was observed onγ-Al_(2)O_(3)(s).Furthermore,no alloying between Pt and Co occurred in PtCo/γ-Al_(2)O_(3)(r),resulting in a reaction rate at 50°C that was merely 11%of that of PtCo/γ-Al_(2)O_(3)(f).The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt,which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species,thereby facilitating the selective oxidation of CO.展开更多
This work synthesized a series of Ni/CeO_(2)/Al_(2)O_(3) catalysts with varying CeO_(2) doping amounts to enhance low-temperature CO_(2) methanation.The introduction of CeO_(2) weakens the interaction between Ni and A...This work synthesized a series of Ni/CeO_(2)/Al_(2)O_(3) catalysts with varying CeO_(2) doping amounts to enhance low-temperature CO_(2) methanation.The introduction of CeO_(2) weakens the interaction between Ni and Al_(2)O_(3),leading to the formation of Ni-CeO_(2) active sites.This results in a high dispersion of Ni and CeO_(2),improved catalyst reducibility,increased number of active sites,and enhanced the CO_(2) methanation.This work further investigated the impact of WHSV and catalyst stacking configuration to enhance the reaction.When the catalyst is stacked into three segments with a temperature gradient of 330℃,300℃,and 250℃under WHSV=9000 ml·h^(-1)·g^(-1),the CO_(2) conversion significantly increases to 95%,which is remarkably close to the thermodynamic equilibrium(96%).展开更多
基金supported by the National Natural Science Foundation of China(22376063,21976057)the Fund of the National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2020A05)Fundamental Research Funds for the Central Universities.
文摘The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influenced by the morphology of the support.Hydrothermal synthesis was employed to produce different morphologies ofγ-Al_(2)O_(3):flower-likeγ-Al_(2)O_(3)(f)exposing(110)crystal faces,sheet-likeγ-Al_(2)O_(3)(s)revealing(100)crystal faces,and rod-likeγ-Al_(2)O_(3)(r)displaying(111)crystal faces,followed by loading PtCo nanoparticles.The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles,and an increase in the alloying degree correlates with enhanced catalyst reactivity.Pt_(3)Co intermetallic compounds were identified onγ-Al_(2)O_(3)(f)exposing(110)crystal faces,and PtCo/γ-Al_(2)O_(3)(f)showed high catalytic activity in the CO-PROX reaction,achieving 100%CO conversion across a broad temperature range of 50−225°C.In contrast,only partial alloying of PtCo was observed onγ-Al_(2)O_(3)(s).Furthermore,no alloying between Pt and Co occurred in PtCo/γ-Al_(2)O_(3)(r),resulting in a reaction rate at 50°C that was merely 11%of that of PtCo/γ-Al_(2)O_(3)(f).The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt,which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species,thereby facilitating the selective oxidation of CO.
基金financial support of the National Natural Science Foundation of China(22178265)Tianjin Science and Technology Project(21JCYBJC00400)Open Project for Ningbo Key Laboratory of Green Petrochemical Carbon Emission Reduction Technology and Equipment(ZITJU2023-ZYDK001).
文摘This work synthesized a series of Ni/CeO_(2)/Al_(2)O_(3) catalysts with varying CeO_(2) doping amounts to enhance low-temperature CO_(2) methanation.The introduction of CeO_(2) weakens the interaction between Ni and Al_(2)O_(3),leading to the formation of Ni-CeO_(2) active sites.This results in a high dispersion of Ni and CeO_(2),improved catalyst reducibility,increased number of active sites,and enhanced the CO_(2) methanation.This work further investigated the impact of WHSV and catalyst stacking configuration to enhance the reaction.When the catalyst is stacked into three segments with a temperature gradient of 330℃,300℃,and 250℃under WHSV=9000 ml·h^(-1)·g^(-1),the CO_(2) conversion significantly increases to 95%,which is remarkably close to the thermodynamic equilibrium(96%).
