CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the ca...CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.展开更多
S123 2003043136USB在单光子计数种子活性快速检测仪中的应用=Applicationof USB to the fast seeds activity analyzer[刊,中]/魏亚东(华南师范大学激光生命科学研究所.广东,广州(510631)),邢达…∥光电子·激光.-2002,13(10).-107...S123 2003043136USB在单光子计数种子活性快速检测仪中的应用=Applicationof USB to the fast seeds activity analyzer[刊,中]/魏亚东(华南师范大学激光生命科学研究所.广东,广州(510631)),邢达…∥光电子·激光.-2002,13(10).-1077-1080研制了一种超微弱发光单光子计数种子活性快速检测仪(FSAA)。该仪器利用单光子计数手段,能够灵敏、直接并有对照性地检测种子的超微弱化学发光(TUCL),获得种子的活力信息。该检测仪可以区分老化程度相差1季的水稻种子的超弱发光。本系统利用Cypress公司的EZ-USB AN2131Q芯片实现了单片数据采集和控制。介绍了通用串行总线(USB)的特点及其在数据采集过程中的优点。图3参6(李瑞琴)展开更多
基金Supported by the National Key Research and Development Program of China(2022YFB4101800)the National Natural Science Foundation of China(22172032,U22A20431)。
文摘CuZnAl(CZA)is a classic industrial catalyst widely used for the synthesis of methanol from syngas,but its catalytic performance is not optimal for the hydrogenation of CO_(2) to methanol.Meanwhile,understanding the catalytic mechanism of Cu species in the CZA catalyst remains a great challenge.In this study,we systematically investigated the valence state change of active Cu species in CZA catalyst and their influence on catalytic performance by modifying the catalysts with varying amounts of electron donor K,thus identifying the catalytic function of Cu species with different valence states.H2-TPR,XPS and HR-TEM characterizations reveal that the highly dispersed K species supported on CZA catalysts will inhibit the reduction of CuO,resulting in a small amount of Cu_(2)O active species being produced under reaction conditions thus causing a decrease in catalytic activity.Furthermore,XRD and Cu LMM spectra show that the proportion of Cu^(0) in K-modified CZA catalysts increases with K loading,but a higher proportion of Cu^(0) species on the surface obviously promotes the reverse water gas shift(RWGS)reaction.According to the results of in situ infrared spectroscopy,CZA catalyst follows the reaction pathway mediated by HCOO^(*)in the hydrogenation of CO_(2) to methanol.
文摘S123 2003043136USB在单光子计数种子活性快速检测仪中的应用=Applicationof USB to the fast seeds activity analyzer[刊,中]/魏亚东(华南师范大学激光生命科学研究所.广东,广州(510631)),邢达…∥光电子·激光.-2002,13(10).-1077-1080研制了一种超微弱发光单光子计数种子活性快速检测仪(FSAA)。该仪器利用单光子计数手段,能够灵敏、直接并有对照性地检测种子的超微弱化学发光(TUCL),获得种子的活力信息。该检测仪可以区分老化程度相差1季的水稻种子的超弱发光。本系统利用Cypress公司的EZ-USB AN2131Q芯片实现了单片数据采集和控制。介绍了通用串行总线(USB)的特点及其在数据采集过程中的优点。图3参6(李瑞琴)
