期刊
APPLIED CATALYSIS A-GENERAL
卷 419, 期 -, 页码 142-147出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.apcata.2012.01.021
关键词
Rhodium; Deactivation; Reduction; In-situ UV-vis; Kinetic analysis
资金
- Grants-in-Aid for Scientific Research [23360354] Funding Source: KAKEN
Kinetic analysis of reduction of Rh/Al2O3 with low Rh-loadings (0.01-0.1 wt%) has been carried out by time resolved in-situ UV-vis spectroscopy. Based on XAFS and UV-vis spectra, it was indicated that Rh was present as surface isolated Rh3+ on catalyst calcined at 773 K in air. The rate of reduction of Rh3+ to metallic Rh was determined by in-situ UV-vis measurements under a flow of 1%H-2/He at 523-823 K. The reduction rate increased with Rh-loading but decreased as the calcination temperature elevated. The decrease of metallic Rh-0 formation with the calcination temperature was in harmony with the reaction rate of CO oxidation. The apparent activation energy (E-a) for the reduction of Rh3+ to Rh-0 was found to be constant around 60-62 kJ mol(-1) and independent of the calcination temperature and the Rh-loading, indicating the equivalent intrinsic activity of supported Rh species on Rh/Al2O3 with the low Rh-loadings. (C) 2012 Elsevier B.V. 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