期刊
JOURNAL OF CATALYSIS
卷 364, 期 -, 页码 354-365出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcat.2018.06.002
关键词
Rhodium; Phenol hydrogenation; Cyclohexanone; Particle size; Site specificity; Thiol-modification
资金
- National University of Singapore [R-143-000-667-114]
- NUS research scholarship
A silica-supported rhodium catalyst for the selective hydrogenation of phenol to cyclohexanone under mild conditions has been developed. As the Rh concentration on the catalyst increased from 6.5 to 15 wt%, the conversion (at phenol/Rh mole ratio 100/1) dropped whereas the initial selectivity to cyclohexanone increased. The direct hydrogenation to cyclohexanol occurred in parallel with partial hydrogenation to cyclohexanone. The negative correlation between selectivity and Rh dispersion suggests that direct hydrogenation occurs at low coordination sites whereas dissociation of phenol to phenoxy followed by hydrogenation to cyclohexanone takes place at higher coordinated terrace sites. DFT calculations revealed that the activation barrier for O-H bond cleavage is lower for phenol adsorbed on a Rh(1 1 1) flat surface than on small particles. By blocking the low coordination edge and step sites through grafting with (3-mercaptopropyl)trimethoxysilane, the cyclohexanone selectivity was improved from 82 to 93% at 100% conversion. The catalyst is active at room temperature and 1 atm H-2 pressure and can be easily activated by in-situ reduction. (C) 2018 Elsevier Inc. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据