The induction behavior in CO2 hydrogenation was studied by varying the reaction temperature to investigate the adaptation of the Cu/ZnO/Al2O3 catalyst to the temperature change. The results indicated that a used catal...The induction behavior in CO2 hydrogenation was studied by varying the reaction temperature to investigate the adaptation of the Cu/ZnO/Al2O3 catalyst to the temperature change. The results indicated that a used catalyst had a tendency to keep the last running state in new reaction conditions for MeOH formation, and that this tendency was related to the difference in Cu/Cun+ ratio caused by CO2 and CO produced at different reaction temperatures. However, the reverse water-gas shift reaction (RWGS) induced at four temperatures was completely different from that of methanol synthesis. It implied that the two so-called competitive reactions in CO2+H2, RWGS and methanol synthesis, have different active centers.展开更多
Cu-based catalysts with excellent activity at low temperatures are widely used for methanol steam reforming(MSR)but suffer from deactivation problems.The present work aims to elucidate the deactivation and regeneratio...Cu-based catalysts with excellent activity at low temperatures are widely used for methanol steam reforming(MSR)but suffer from deactivation problems.The present work aims to elucidate the deactivation and regeneration mechanisms of the commercial Cu/ZnO/Al_(2)O_(3) catalyst in low temperature MSR.By employing a series of(quasi)in situ characterization methods,it is found that the deactivation of the catalyst at a high weight hourly space velocity(WHSV)and a low reaction temperature is mainly due to the poisoning of Cu species associated with surface-oxygenated species with less Cu sintering,rather than carbon deposition,and strong metal-support interaction(SMSI).An in situ regeneration method was developed for the deactivated commercial Cu/ZnO/Al_(2)O_(3) catalyst via the simultaneous supply of O_(2).It is shown that the addition of O_(2)(≥1 vol%)can reverse the deactivation caused by surface-oxygenated poisoning due to the weak interaction between formed surface copper oxide and surface-oxygenated species,facilitating their desorption,but not deactivation caused by sintering,thereby partially restoring the catalytic activity.展开更多
Cu/ZnO/Al_(2)O_(3) catalysts with Cu/Zn/Al ratios of 6/3/1 were precipitated and aged by conventional and microwave heating methods and tested in the slurry phase reactor for methanol synthesis.The effect of technolog...Cu/ZnO/Al_(2)O_(3) catalysts with Cu/Zn/Al ratios of 6/3/1 were precipitated and aged by conventional and microwave heating methods and tested in the slurry phase reactor for methanol synthesis.The effect of technological condition of precipitation and aging process under microwave irradiation on the catalytic performance was investigated to optimize the preparing condition of Cu/ZnO/Al_(2)O_(3) catalyst.The results showed that the microwave irradiation during precipitation process could improve the activity of the catalyst,but had little effect on the stability.While the microwave irradiation during aging process has a great benefit to both the activity and stability of the catalyst,the catalyst aged at 80℃ for 1 h under microwave irradiation possessed higher methanol space time yield(STY)and more stable catalytic activity.The activity and stability of the catalyst was further enhanced when microwave irradiation was used in both precipitation and aging processes;the optimized condition for the catalyst precursor preparation was precipitation at 60℃ and aging at 80℃ under microwave irradiation.展开更多
A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/...A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.展开更多
文摘The induction behavior in CO2 hydrogenation was studied by varying the reaction temperature to investigate the adaptation of the Cu/ZnO/Al2O3 catalyst to the temperature change. The results indicated that a used catalyst had a tendency to keep the last running state in new reaction conditions for MeOH formation, and that this tendency was related to the difference in Cu/Cun+ ratio caused by CO2 and CO produced at different reaction temperatures. However, the reverse water-gas shift reaction (RWGS) induced at four temperatures was completely different from that of methanol synthesis. It implied that the two so-called competitive reactions in CO2+H2, RWGS and methanol synthesis, have different active centers.
基金sponsored by the National Natural Science Foundation of China (22078089)the Program for Professor of Special Appointment (Eastern Scholar)at Shanghai Institutions of Higher LearningShanghai Sailing Program (19YF1410600)。
文摘Cu-based catalysts with excellent activity at low temperatures are widely used for methanol steam reforming(MSR)but suffer from deactivation problems.The present work aims to elucidate the deactivation and regeneration mechanisms of the commercial Cu/ZnO/Al_(2)O_(3) catalyst in low temperature MSR.By employing a series of(quasi)in situ characterization methods,it is found that the deactivation of the catalyst at a high weight hourly space velocity(WHSV)and a low reaction temperature is mainly due to the poisoning of Cu species associated with surface-oxygenated species with less Cu sintering,rather than carbon deposition,and strong metal-support interaction(SMSI).An in situ regeneration method was developed for the deactivated commercial Cu/ZnO/Al_(2)O_(3) catalyst via the simultaneous supply of O_(2).It is shown that the addition of O_(2)(≥1 vol%)can reverse the deactivation caused by surface-oxygenated poisoning due to the weak interaction between formed surface copper oxide and surface-oxygenated species,facilitating their desorption,but not deactivation caused by sintering,thereby partially restoring the catalytic activity.
基金supported by the National Basic Research Program of China(Grant No.2005CB221204).
文摘Cu/ZnO/Al_(2)O_(3) catalysts with Cu/Zn/Al ratios of 6/3/1 were precipitated and aged by conventional and microwave heating methods and tested in the slurry phase reactor for methanol synthesis.The effect of technological condition of precipitation and aging process under microwave irradiation on the catalytic performance was investigated to optimize the preparing condition of Cu/ZnO/Al_(2)O_(3) catalyst.The results showed that the microwave irradiation during precipitation process could improve the activity of the catalyst,but had little effect on the stability.While the microwave irradiation during aging process has a great benefit to both the activity and stability of the catalyst,the catalyst aged at 80℃ for 1 h under microwave irradiation possessed higher methanol space time yield(STY)and more stable catalytic activity.The activity and stability of the catalyst was further enhanced when microwave irradiation was used in both precipitation and aging processes;the optimized condition for the catalyst precursor preparation was precipitation at 60℃ and aging at 80℃ under microwave irradiation.
基金supported by the National Key R&D Program of China(2021YFA1501100)the National Natural Science Foundation of China(22005007)+1 种基金the New Cornerstone Science Foundation,and Liaoning Binhai Laboratory Project(LBLF-202306)the Tencent Foundation through the XPLORER PRIZE.
文摘A hydrogen storage system was developed via heterogeneous catalysis,employing the dehydrogenative coupling of methanol and N,N′-dimethylethylenediamine to efficiently produce high-purity H_(2).In this process,the Cu/ZnO/Al_(2)O_(3) catalyst displayed superior activity in hydrogen production,with Cu+identified as the major active site through comprehensive characterization.
