| Autor: |
Sean M. McClure, Mingshu Chen, Y. Cai, Q. Guo, D. W. Goodman, Feng Gao, Yixuan Wang, Kerrie K. Gath |
| Rok vydání: |
2009 |
| Předmět: |
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| Zdroj: |
Surface Science. 603:65-70 |
| ISSN: |
0039-6028 |
| DOI: |
10.1016/j.susc.2008.10.031 |
| Popis: |
The CO oxidation reaction on Pt-group metals (Pt, Rh, and Pd) has been investigated at low (⩽10−3 Torr) and near atmospheric (1–102 Torr) pressures in a batch reactor under steady-state conditions and at various gaseous reactant compositions using PM-IRAS and kinetic measurements. The results indicate that Langmuir–Hinshelwood kinetics adequately provides a general description of the kinetic trends over a wide range of pressures provided that mass transfer effects are considered. At high pressures, the reaction kinetics fall into three regimes: a CO-inhibited low temperature regime where the reaction rate is determined by CO desorption; a mass transfer limited regime at high temperatures; and a transient, high-rate regime which lies in between the other two regimes. The data show that the most reactive surface phase, at both low and high pressures, is a CO-uninhibited phase. This surface phase is not an oxide phase, but a surface phase that contains primarily chemisorbed atomic oxygen and a low coverage of CO. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect