Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency h...Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency has been severely hampered by the lack of highly active catalytic sites.Moreover,due to the intrinsic thermodynamic stability and kinetic inertia of CO_(2)and the higher energy barrier of the ring-opening reaction of epoxides,the heterogeneous catalytic conversion of CO_(2)highly depends on harsh operating conditions,high temperatures and pressures,and the incorporation of cocatalysts.The devel-opment of efficient heterogeneous catalysts for CO_(2)conversion under cocatalyst-free and mild conditions has always been a challenge.Herein,we have proposed a synergetic strategy of facet and vacancy engi-neering for the construction of highly efficient heterogeneous catalyst BiO1-x Br1-y-(010)for CO_(2)cycload-dition,where introducing the OVs-BrVs pairs into typical(010)facets BiOBr with simultaneous surface Lewis acid sites Bi^(3+)and nucleophilic sites Br^(−).By combining theoretical calculations and a series of systematic experiments,such as CO_(2)temperature-programmed desorption,electron paramagnetic res-onance and fluorescence probe analysis experiments,the introduced OVs-BrVs pair can not only form Bi^(3+)-Bi^(3-x)+dual active sites on the surface,which activate PO and CO_(2)respectively to reduce the energy barrier of CO_(2)insertion,but also activate Br^(−)near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening.As a result,the BiO1-x Br1-y-(010)with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99%with 100%selectivity un-der cocatalyst-free and mild conditions,far surpassing most heterogeneous catalytic systems.This work provides a completely new strategy to construct high-performance heterogeneous CO_(2)cycloaddition cata-lysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.展开更多
基金supported by the National Science Basic Research Program of Shaanxi(Nos.2024JC-YBQN-0103,2024JC-YBMS-127,2022JQ-102)the National Natural Science Foundation of China(No.52073228)the Xi’an Shiyou University Postgraduate Innovation and Practical Ability Training Project(No.YCS23213089).
文摘Among the many strategies for CO_(2)resource utilization,the synthetic technology of cyclic carbonates with 100%atom economy through CO_(2)and epoxide is one of the most industrially viable routes,but its efficiency has been severely hampered by the lack of highly active catalytic sites.Moreover,due to the intrinsic thermodynamic stability and kinetic inertia of CO_(2)and the higher energy barrier of the ring-opening reaction of epoxides,the heterogeneous catalytic conversion of CO_(2)highly depends on harsh operating conditions,high temperatures and pressures,and the incorporation of cocatalysts.The devel-opment of efficient heterogeneous catalysts for CO_(2)conversion under cocatalyst-free and mild conditions has always been a challenge.Herein,we have proposed a synergetic strategy of facet and vacancy engi-neering for the construction of highly efficient heterogeneous catalyst BiO1-x Br1-y-(010)for CO_(2)cycload-dition,where introducing the OVs-BrVs pairs into typical(010)facets BiOBr with simultaneous surface Lewis acid sites Bi^(3+)and nucleophilic sites Br^(−).By combining theoretical calculations and a series of systematic experiments,such as CO_(2)temperature-programmed desorption,electron paramagnetic res-onance and fluorescence probe analysis experiments,the introduced OVs-BrVs pair can not only form Bi^(3+)-Bi^(3-x)+dual active sites on the surface,which activate PO and CO_(2)respectively to reduce the energy barrier of CO_(2)insertion,but also activate Br^(−)near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening.As a result,the BiO1-x Br1-y-(010)with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99%with 100%selectivity un-der cocatalyst-free and mild conditions,far surpassing most heterogeneous catalytic systems.This work provides a completely new strategy to construct high-performance heterogeneous CO_(2)cycloaddition cata-lysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.
