文献类型：期刊文献

英文题名：Regulating mesopore structures of support toward enhanced selective hydrogenation of dimethyl oxalate to methyl glycolate on Ag catalysts

作者：Luo, Zuwei[1];Xu, Xiaofeng[2];Dong, Guilin[2];Cao, Yueqiang[2];Hu, Shen[1];Ye, Guanghua[1];Zhu, Yi-An[1];Zhou, Jinghong[1,2];Li, Wei[2];Zhou, Xinggui[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem Engn, 130 Meilong Rd, Shanghai 200237, Peoples R China

年份：2022

卷号：450

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20223212545073);WOS:【SCI-EXPANDED(收录号:WOS:000849767900002)】；

基金：This work was supported by Ministry of Science and Technology of the Peoples Republic of China, under the Research Fund for National Key R & D Program of China (2018YFB0604700) , the Natural Science Foundation of China (22008067, 22178102 and 22073027) , and the China Postdoctoral Science Foundation (2020M681202 and 2021T140204).

语种：英文

外文关键词：DMO hydrogenation; Methyl glycolate; Mesopore structure; Diffusion; Ag catalyst

摘要：Precisely regulating mesopore structures toward enhanced diffusion of reactants and targeted product is of great significance for achieving simultaneously improved activity and selectivity, which is exemplified by this work employing mesoporous silica with distinct structured mesopores as support for Ag catalysts to selectively hydrogenate dimethyl oxalate (DMO) into methyl glycolate (MG). Mesopomus silica nanosphere (MSNS) with center-radial pores shows shorter pore length than SBA-15 with parallel mesopores, which is beneficial for the diffusion process and thus gives rise to enhanced hydrogenation activity. Inspired by these insights, MSNSs sized in 50, 90, 120 and 160 nm are further synthesized to regulate pore length and systematically explore their effects on the reaction. The diffusion process is enhanced with decreasing the size of MSNS from 160 to 50 nm, as elucidated by the effective diffusion time constant (D-e/R-2) determined by zero-length column (ZLC) method. Accordingly, DMO can facilely diffuse into the mesopores with shorter length to access the active sites while the formed MG product can easily diffuse out to avoid the over-hydrogenation process, which is corroborated by the comparison for performances of these Ag/MSNSs catalysts. Notably, a moderately short pore length, balancing well the diffusion and hydrogenation process, is more preferable for achieving both higher activity and better selectivity to MG, and MSNS sized in 90 nm supported Ag catalyst thus exhibits the greatest performances, with MG selectivity up to 96.6 % at 99.7 % of DMO conversion.