Mechanistic insights into propylene oxidation to acrolein over gold catalysts  

作　　者：Bin Lin Wenyao Chen Nan Song Zhihua Zhang Qianhong Wang Wei Du Xinggui Zhou Xuezhi Duan 

机构地区：[1]State Key Laboratory of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第5期39-49,共11页中国化学工程学报（英文版）

基　　金：financially supported by the Research Fund for National Key Research and Development Program of China (2021YFA1501403);the National Natural Science Foundation of China (22208094,22038003,21922803,22178100);the Innovation Program of Shanghai Municipal Education Commission,the Program of Shanghai Academic/Technology Research Leader (21XD1421000);the Shanghai Science and Technology Innovation Action Plan (22JC1403800)。

摘　　要：Direct epoxidation of propylene with H_(2)/O_(2),being the dream reaction for propylene oxide(PO)production,has raised wide scientific and industrial interests.Fundamentally understanding the formation mechanism of acrolein,as the main by-product of this epoxidation process,is very important to achieve the high yield of PO.In this study,we perform the spin-polarized density functional theory(DFT)calculations to investigate the reaction pathway from propylene to acrolein over two representative Au surfaces,that is,Au(111)and Au(100),which incorporates propylene adsorption,methyl hydrogen activation and acrolein formation.The results show that the oxygenated species(mainly O^(*),OH^(*)and OOH^(*))are able to stabilize the adsorption of propylene to decrease the energy barrier for its activation.It is demonstrated that the OOH^(*)on Au(111)surface emerges as the most easily formed oxygenated species via the H-assisted O_(2) dissociation,which is also the most active for the cleavage of methyl CAH bond in propylene.Furthermore,three pathways of acrolein formation activated by O^(*)/OH^(*)/OOH^(*)are analyzed,in which O^(*)is found as the key species to form acrolein.Finally,Bader charge analysis was conducted to explore the reasons behind the promotion effect of the oxygenated species.The insights reported here could be valuable in the design and optimization of gold catalysts for the direct epoxidation of propylene.

关 键 词：Acrolein formation Oxygenated species DFT calculations Au surfaces Reaction mechanism 

分 类 号：TQ426[化学工程] TQ224.132