The metal promoted In_(2)O_(3) catalysts for CO_(2) hydrogenation to methanol have attracted wide attention because of their high activity with high methanol selectivity.However,there was still no experimental confirm...The metal promoted In_(2)O_(3) catalysts for CO_(2) hydrogenation to methanol have attracted wide attention because of their high activity with high methanol selectivity.However,there was still no experimental confirmation if copper could be a good promoter for In_(2)O_(3).Herein,the Cu promoted In_(2)O_(3) catalyst was prepared using a deposition-precipitation method.Such prepared Cu/In_(2)O_(3) catalyst shows significantly higher CO_(2) conversion and space time yield(STY)of methanol,compared to the un-promoted In_(2)O_(3) catalyst.The loading of Cu facilitates the activation of both H_(2) and CO_(2) with the interface between the Cu cluster and defective In_(2)O_(3) as the active site.The Cu/In_(2)O_(3) catalyst takes the CO hydrogenation pathway for methanol synthesis from CO_(2) hydrogenation.It exhibits a unique size effect on the CO adsorption.At temperatures below 250℃,CO adsorption on Cu/In_(2)O_(3) is stronger than that on In_(2)O_(3),causing higher methanol selectivity.With increasing temperatu res,the Cu catalyst aggregates,which leads to the formation of weak CO adsorption site and causes a decrease in the methanol selectivity.Compared with other metal promoted In_(2)O_(3) catalysts,it can be concluded that the catalyst with stronger CO adsorption possesses higher methanol selectivity.展开更多
Indium oxide supported nickel catalyst has been experimentally confirmed to be highly active for CO_(2) hydrogenation towards methanol.In this work,the reaction mechanism for CO_(2) hydrogenation to methanol has been ...Indium oxide supported nickel catalyst has been experimentally confirmed to be highly active for CO_(2) hydrogenation towards methanol.In this work,the reaction mechanism for CO_(2) hydrogenation to methanol has been investigated on a model Ni/In_(2)O_(3) catalyst,i.e.,Ni_(4)/In_(2)O_(3),via the density functional theory(DFT)study.Three possible reaction pathways,i.e.,the formate pathway,CO hydrogenation and the reverse water-gas-shift(RWGS)pathways,have been examined on this model catalyst.It has been demonstrated that the RWGS pathway is the most theoretically-favored for CO_(2) hydrogenation to methanol.The complete RWGS pathway follows CO_(2)+6 H→COOH+5 H→CO+H_(2)O+4 H→HCO+H_(2)O+3 H→H_(2)CO+H_(2)O+2 H→H_(3)CO+H_(2)O+H→H_(3)COH+H_(2) O.Furthermore,it has been also proved that the interfacial oxygen vacancy can serve as the active site for boosting the CO_(2) adsorption and charge transfer between the nickel species and indium oxide,which synergistically promotes the consecutive CO_(2) hydrogenation towards methanol.展开更多
Aryl diazonium salts occupy a privileged role in synthetic chemistry owing to their ready availability and versatile reactivity.While their applications in accessing diversely functionalized arene derivatives via deni...Aryl diazonium salts occupy a privileged role in synthetic chemistry owing to their ready availability and versatile reactivity.While their applications in accessing diversely functionalized arene derivatives via denitrogenation-coupling and reduction/addition reactions have been well recognized by practitioners in both academia and industry,recent renaissance in chemical transformations of retaining the key N2-unit has emerged as a powerful technique to construct various A/-heterocycles.This review covers the history and latest advances in cyclization and cycloaddition reactions using aryl diazonium salts as N2-annulation synthons.The scope,applications,and opportunities in exploring new chemical space by this sustainable strategy are summarized and discussed.展开更多
基金supported by the National Natural Science Foundation of China(22138009)the Fundamental Research Funds for the Central Universities of China。
文摘The metal promoted In_(2)O_(3) catalysts for CO_(2) hydrogenation to methanol have attracted wide attention because of their high activity with high methanol selectivity.However,there was still no experimental confirmation if copper could be a good promoter for In_(2)O_(3).Herein,the Cu promoted In_(2)O_(3) catalyst was prepared using a deposition-precipitation method.Such prepared Cu/In_(2)O_(3) catalyst shows significantly higher CO_(2) conversion and space time yield(STY)of methanol,compared to the un-promoted In_(2)O_(3) catalyst.The loading of Cu facilitates the activation of both H_(2) and CO_(2) with the interface between the Cu cluster and defective In_(2)O_(3) as the active site.The Cu/In_(2)O_(3) catalyst takes the CO hydrogenation pathway for methanol synthesis from CO_(2) hydrogenation.It exhibits a unique size effect on the CO adsorption.At temperatures below 250℃,CO adsorption on Cu/In_(2)O_(3) is stronger than that on In_(2)O_(3),causing higher methanol selectivity.With increasing temperatu res,the Cu catalyst aggregates,which leads to the formation of weak CO adsorption site and causes a decrease in the methanol selectivity.Compared with other metal promoted In_(2)O_(3) catalysts,it can be concluded that the catalyst with stronger CO adsorption possesses higher methanol selectivity.
基金supported by the National Natural Science Foundation of China (Nos. 21536008 and 21621004).
文摘Indium oxide supported nickel catalyst has been experimentally confirmed to be highly active for CO_(2) hydrogenation towards methanol.In this work,the reaction mechanism for CO_(2) hydrogenation to methanol has been investigated on a model Ni/In_(2)O_(3) catalyst,i.e.,Ni_(4)/In_(2)O_(3),via the density functional theory(DFT)study.Three possible reaction pathways,i.e.,the formate pathway,CO hydrogenation and the reverse water-gas-shift(RWGS)pathways,have been examined on this model catalyst.It has been demonstrated that the RWGS pathway is the most theoretically-favored for CO_(2) hydrogenation to methanol.The complete RWGS pathway follows CO_(2)+6 H→COOH+5 H→CO+H_(2)O+4 H→HCO+H_(2)O+3 H→H_(2)CO+H_(2)O+2 H→H_(3)CO+H_(2)O+H→H_(3)COH+H_(2) O.Furthermore,it has been also proved that the interfacial oxygen vacancy can serve as the active site for boosting the CO_(2) adsorption and charge transfer between the nickel species and indium oxide,which synergistically promotes the consecutive CO_(2) hydrogenation towards methanol.
基金This work was supported by the National Key Research and Development Program of China(2019YFA0905100)the National Natural Science Foundation of China(Nos.21772142,21901181,and 21971186)Tianjin Municipal Science&Technology Commission(19JCQNJC04700).
文摘Aryl diazonium salts occupy a privileged role in synthetic chemistry owing to their ready availability and versatile reactivity.While their applications in accessing diversely functionalized arene derivatives via denitrogenation-coupling and reduction/addition reactions have been well recognized by practitioners in both academia and industry,recent renaissance in chemical transformations of retaining the key N2-unit has emerged as a powerful technique to construct various A/-heterocycles.This review covers the history and latest advances in cyclization and cycloaddition reactions using aryl diazonium salts as N2-annulation synthons.The scope,applications,and opportunities in exploring new chemical space by this sustainable strategy are summarized and discussed.