文献类型：期刊文献

英文题名：Understanding size-dependent hydrogenation of dimethyl oxalate to methyl glycolate over Ag catalysts

作者：Dong, Guilin[1];Luo, Zuwei[1];Cao, Yueqiang[2];Zheng, Sainan[3];Zhou, Jinghong[2];Li, Wei[1];Zhou, Xinggui[2]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, State Key Lab Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[3]Pujing Chem Ind Co Ltd, 166 Minhong Rd, Shanghai 201102, Peoples R China

年份：2021

卷号：401

起止页码：252

外文期刊名：JOURNAL OF CATALYSIS

收录：;EI(收录号：20213410793041);WOS:【SCI-EXPANDED(收录号:WOS:000691529200010)】；

基金：This work was supported by Ministry of Science and Technology of the People's Republic of China, under the Research Fund for National Key R&D Program of China (2018YFB0604700), the Natural Science Foundation of China (22008067), and the China Postdoctoral Science Foundation (2020M681202 and 2021T140204).

语种：英文

外文关键词：DMO hydrogenation; Methyl glycolate; Silver catalyst; Structure sensitivity; Active sites

摘要：Ag catalysts are promising for the selective hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG), where the size of Ag nanoparticles strongly dominates their catalytic performances. Fundamental understandings on the size dependence, especially at the level of active sites, are still lacking but of great importance for the rational design of Ag-based catalysts for this reaction. Herein, a series of catalysts con-sisting of Ag nanoparticles sized from 2.9 to 8.8 nm anchored on amine-derivatized mesoporous silica nanospheres (Ag/AS) were synthesized and employed to understand the size-dependent DMO hydro-genation to MG. A volcano-shape trend between the hydrogenation activity and the increasing Ag particle size is observed for the differently sized Ag/AS catalysts, indicating a remarkable size dependence. The origin of the size dependence is further understood based on the cuboctahedron model of Ag nanoparti-cle, and the step-likes active sites are identified as the dominant ones. Results combining with the X-ray photoelectron spectroscopy, in situ Fourier transform infrared spectroscopy and temperature pro-grammed desorption studies, indicate that the hydrogenation of DMO to MG on Ag/AS catalysts is mainly dominated by the number of active sites when the Ag particle size > 5.3 nm, but by the electronic prop-erties when the Ag particle size < 5.3 nm. The balance between the number of active sites and electronic structure gives rise to a maximal reaction rate in term of apparent TOF on the Ag/AS catalyst with Ag par-ticle size of 5.3 nm. These understandings may guide the design of highly efficient Ag catalysts for the coal-based MG production. (c) 2021 Elsevier Inc. All rights reserved.