Engineering the Reactivity of Metal Catalysts: A Model Study of Methane Dehydrogenation on Rh(111)
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- 作者：Anton Kokalj ; Nicola Bonini ; Carlo Sbraccia ; Stefano de Gironcoli ; and Stefano Baroni
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：December 29, 2004
- 年：2004
- 卷：126
- 期：51
- 页码：16732 - 16733
- 全文大小：120K
- 年卷期：v.126,no.51(December 29, 2004)
- ISSN：1520-5126
文摘
The first two steps of methane dissociation on Rh(111) have been investigated using density-functional theory, focusing on the dependence of the catalyst's reactivity on the atomic coordination of the active metal site. We find that, although the barrier for the dehydrogenation of methane (CH4 
CH3 + H) decreases as expected with the coordination of the binding site, the dehydrogenation of methyl (CH3 CH2 + H) is hindered at an ad-atom defect, where the first reaction is instead most favored. Our findings indicate that, if it were possible to let the dissociation occur selectively at ad-atom defects, the reaction could be blocked after the first dehydrogenation step, a result of high potential interest for many dream reactions such as, for example, the direct conversion of methane to methanol.
CH3 + H) decreases as expected with the coordination of the binding site, the dehydrogenation of methyl (CH3 CH2 + H) is hindered at an ad-atom defect, where the first reaction is instead most favored. Our findings indicate that, if it were possible to let the dissociation occur selectively at ad-atom defects, the reaction could be blocked after the first dehydrogenation step, a result of high potential interest for many dream reactions such as, for example, the direct conversion of methane to methanol.