文献类型：期刊文献

英文题名：Using ammonia solution to fabricate highly active Au/uncalcined TS 1 catalyst for gas-phase epoxidation of propylene

作者：Zhang, Zhihua[1];Shi, Shudong[1];Tang, Yanqiang[1];Xu, Jialun[1];Du, Wei[1];Wang, Qianghong[1];Yu, Daiyi[1];Liao, Yujie[1];Song, Nan[1];Duan, Xuezhi[1];Zhou, Xinggui[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2022

卷号：416

起止页码：410

外文期刊名：JOURNAL OF CATALYSIS

收录：;EI(收录号：20230213352413);WOS:【SCI-EXPANDED(收录号:WOS:000901490900006)】；

基金：This work was financially supported by the Ministry of Science and Technology of the People's Republic of China under the Research Fund for National Key R&D Program of China (2021YFA1501403) , the Natural Science Foundation of China (22038003, 22208093, 22178100 and 21922803) , the Innovation Program of the Shanghai Municipal Education Commission, the Program of Shanghai Academic/Technology Research Leader (21XD1421000) and the Shanghai Science and Technology Innova-tion Action Plan (22JC1403800) .

语种：英文

外文关键词：Propylene epoxidation; Gold particles; Defective Ti species; Modified DP method; Ammonia treatment

摘要：Reducing the Au particle size and increasing the number of defective Ti4+ species have been considered effective strategies to boost the catalytic performance of Au-Ti bifunctional catalysts used for propylene epoxidation utilizing H2 and O2. Consequently, the development of an effective method that can simul-taneously achieve these goals is of significant scientific and industrial importance. Herein, we demon-strate, for the first time, that the simultaneous immobilization of small Au particles (approximately 1.6 nm) onto uncalcined titanium silicate-1 (i.e., TS-1-B) and facilitation of the formation of defective Ti4+ species can be achieved using a modified deposition-precipitation (DP) method utilizing ammonia solution as the precipitant. The as-synthesized catalyst exhibits a significantly enhanced propylene oxide (PO) formation rate combined with fascinating PO selectivity and hydrogen efficiency, which were better than the reference catalyst prepared via the DP urea (DPU) method and other reported Au/uncalcined TS-1 catalysts. The catalyst structure-performance relationship was established using multiple charac-terization studies. the ammonia treatment facilitates the hydrolysis of some of the-Ti-O -Si-bonds into defective Ti4+ species (i.e., Ti(OSi)3OH), which not only provides more active Ti4+ sites but also favors the uniform deposition of Au. This methodology and the insights stated herein may also be applicable for enhancing the dispersion of Au in a variety of zeolite-supported catalysts.(c) 2022 Elsevier Inc. All rights reserved.