CO hydrogenation on stepped Cu and CuZn alloy surfaces:Competition between methanol synthesis and methanation pathways  

作　　者：Xuanye Chen Wenhua Zhang Weixin Huang 

机构地区：[1]School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,China [2]Research Institute of Applied Chemistry,Jiangxi Academy of Sciences,Nanchang 330096,China

出　　处：《Chinese Chemical Letters》2023年第7期463-466,共4页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 91745202, 92145302);the Chinese Academy of Sciences, the Changjiang Scholars Program of Ministry of Education of China。

摘　　要：Comprehensive fundamental understanding of CO hydrogenation reactions over Cu and ZnCu alloy surfaces is of great importance.Herein,we report a comparative DFT calculation study of elementary surface reaction network of CO hydrogenation reactions on stepped Cu(211),Cu(611),ZnCu(211) and ZnCu(611)surfaces.On Zn Cu(211) and Zn Cu(611) surfaces,the energetic favorable reaction path of CO hydrogenation reaction follows CO^(*)→HCO^(*)→H_(2)CO^(*)→H_(3)CO^(*)→CH_(3)OH^(*)→CH_(3)OH with H_(3)CO^(*)hydrogenation as the rate-limiting step and proceeds more facilely on ZnCu(611) surface than on ZnCu(211) surface.On Cu(211) and Cu(611) surfaces,the energetic favorable reaction path of CO hydrogenation reaction follows CO^(*)→HCO^(*)→HCOH^(*)→H_(2)COH^(*)→H_(3)COH^(*)→CH_(3)^(*)→CH_(4)^(*)→CH_(4) with H_(2)COH^(*) hydrogenation as the rate-limiting step and proceeds more facilely on Cu(611) than on Cu(211).The key difference of CO hydrogenation reaction on Zn Cu alloy surface and Cu is that the resulting CH_(3)OH^(*) species desorbs to produce CH_(3)OH on ZnCu alloy but undergoes H^(*)-assisted decomposition to CH_(3)^(*) and eventually to CH_(4) on Cu surface.These results successfully unveil elementary surface reaction networks and structure sensitivity of Cu and Zn Cu alloy-catalyzed CO hydrogenation reactions.

关 键 词：Theoretical calculation Reaction mechanism Structure-activity relation Facet effect Defect 

分 类 号：TQ203.2[化学工程—有机化工]