Kinetics and mechanistic insights into the active sites of Au catalysts for selective propylene oxidation  

作　　者：Qianhong Wang Zhihua Zhang Keng Sang Wenyao Chen Gang Qian Jing Zhang Xinggui Zhou Xuezhi Duan 

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

出　　处：《Nano Research》2023年第5期6220-6227,共8页纳米研究（英文版）

基　　金：the National Key R&D Program of China(No.2021YFA1501403);the National Natural Science Foundation of China(Nos.21922803,22038003,92034301,22008066,and 21776077);the Innovation Program of Shanghai Municipal Education Commission,the Program of Shanghai Academic/Technology Research Leader(No.21XD1421000);the Shanghai Science and Technology Innovation Action Plan(No.22JC1403800);the China Postdoctoral Science Foundation(No.BX20190116);111 Project of the Ministry of Education of China(No.B08021).

摘　　要：Identification of the catalytically active sites emerges as the prerequisite for an atomic-level comprehensive understanding and further rational design of highly efficient catalysts.Here,we demonstrate a kinetics strategy to identify the active sites of Au catalyst for the disentanglement of geometric and electronic effects on the selective oxidation of propylene to acrolein.Both the Ti-containing titanium-silicalite-1(TS-1)and Ti-free silicalite-1(S-1)were employed as supports to immobilize Au catalysts,which were investigated by a combination of multiple characterization,kinetics analysis,crystal structure modelling.The Au(111)sites are identified as the main active site for acrolein formation,while their electronic effects are highly relevant to the presence or absence of Ti.Moreover,propylene epoxide(PO)formation mainly involves the co-participation of Au and Ti sites,the proximity between Au and Ti sites is found to have less influences on PO formation in a certain distance.In comparison,acrolein is very likely to generate over Au(111)sites via the hydrogen-assisted O_(2) activation to oxygenated species for its oxidizing propylene.The insights gained here could guide the design and preparation of Au catalysts for selective propylene oxidation.

关 键 词：propylene oxidation Au catalysts active site geometric and electronic effects Au-Ti proximity 

分 类 号：O64[理学—物理化学]