文献类型：期刊文献

英文题名：Understanding Catalytic Reactions over Zeolites: A Density Functional Theory Study of Selective Catalytic Reduction of NOx by NH3 over Cu-SAPO-34

作者：Mao, Yu[1,2];Wang, Ziyun[2];Wang, Hai-Feng[1];Hu, P.[1,2]

机构：[1]East China Univ Sci & Technol, Key Lab Adv Mat, Ctr Computat Chem & Res, Inst Ind Catalysis, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT9 5AG, Antrim, North Ireland

年份：2016

卷号：6

期号：11

起止页码：7882

外文期刊名：ACS CATALYSIS

收录：;EI(收录号：20164603012720);WOS:【SCI-EXPANDED(收录号:WOS:000387306100071)】；

基金：This project was supported by the National Key Basic Research Program of China (2013CB933201), the National Natural Science Foundation of China (21303052, 21333003, 21622305), Shanghai Rising-Star Program (14QA1401100), "Chen Guang" project (13CG24), Young Elite Scientist Sponsorship Program by CAST, Fundamental Research Funds for the Central Universities, and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase). The authors gratefully acknowledge the U.K's national high performance computing service ARCHER (for which access was obtained via the UKCP consortium) for computing time. Y.M. thanks the Queen's University of Belfast and Chinese Scholarship Council for a joint scholarship.

语种：英文

外文关键词：Cu-SAPO-34; density functional theory; selective catalytic reduction; ammonia; zeolite; nitric oxide

摘要：Metal-exchanged CHA-type (SAPO-34 and SSZ-13) zeolites are promising catalysts for selective catalytic reduction (SCR) of NOx by NH3. However, an understanding of the process at the molecular level is still limited, which hinders the identification of its mechanism and the design of more efficient zeolite catalysts. In this work, modeling the reaction over Cu-SAPO-34, a periodic density functional theory (DFT) study of NH3-SCR was performed using the hybrid functional (HSE06) with the consideration of van der Waals (vdW) interactions. A mechanism with a low N-N coupling barrier is proposed to account for the activation of NO. The redox cycle of Cu2+ and Cu+, which is crucial for the SCR process, is identified with detailed analyses. In addition, the decomposition of NH2NO is shown to readily occur on the Bronsted acid site by a hydrogen push-pull mechanism, confirming the collective efforts of Bronsted acid and Lewis acid (Cu2+) sites. The special electronic and structural properties of Cu-SAPO-34 are demonstrated to play an essential role in the reaction, which may have general implications on the understanding of zeolite catalysis.