4.8 Article

Microkinetic analysis of acetone hydrogenation over Pt/SiO2

期刊

JOURNAL OF CATALYSIS
卷 374, 期 -, 页码 183-198

出版社

ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.jcat.2019.04.033

关键词

Acetone hydrogenation; Ketone hydrogenation; Platinum; Silica; Kinetics; Microkinetic modelling; Horiuti-Polanyi

资金

  1. National Science Foundation of the United States of America [CBET-1159739, CBET-1159863]

向作者/读者索取更多资源

The kinetics of vapor-phase acetone hydrogenation were investigated over a Pt/SiO2 catalyst through a range of temperatures (303-435 K) and reactant partial pressures (p(ACE) = 0.3-140 Torr, p(H2) = 100-930 Torr). We compile macroscopically observable reaction orders, apparent barriers, kinetic isotope effects, and reaction rates; and we present a microkinetic analysis that considers multiple rate control scenarios in two Horuiti-Polanyi-type mechanisms. Overall, our data are best described by a two-site model wherein atomic hydrogen adsorbs at a distinct set of active sites from organic species. We further propose that two surface reactions each exert partial rate control, and we illustrate that degree of rate control is sensitive to reaction conditions. Shifts in rate control are attributed primarily to changing surface coverage regimes, which highlights the significance of both free energies of activation and chemicalpotential driving forces in dictating the kinetic significance of elementary steps. Despite our conclusion that surface reactions involving H-X bond formation are likely rate controlling, we observe that H-2/D-2 switching minimally perturbs acetone hydrogenation rates. We interpret this by considering that observed kinetic isotope effects reflect a convolution of kinetic and thermodynamic impacts, which can obscure the elementary effects of changes in isotopic mass. (C) 2019 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。

评论

主要评分

4.8
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据