Why is a noble metal catalytically active? The role of the O-Ag interaction in the function of silver as an oxidation catalyst
Why is a noble metal catalytically active? The role of the O-Ag interaction in the function of silver as an oxidation catalyst
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DOI：
10.1103/physrevlett.90.256102
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发表时间：
2003-06-27
影响因子：
8.6
通讯作者：
Scheffler, M
中科院分区：
文献类型：
--
作者：
Li, WX;Stampfl, C;Scheffler, M
广泛的密度泛函理论计算，并考虑到温度和压力，提供了氧和银（111）的行为和相互作用的全面图片，并提供了有价值的洞察银作为氧化催化剂的功能。所获得的相图揭示了在给定环境中存在的最稳定的物种，从而识别（并排除）可能的活性氧物种。特别是，对于乙烯环氧化的条件下，薄oxidelike结构是最稳定的，这表明，这种原子O物种的催化，在迄今提出的molecularlike物种相反。
Extensive density-functional theory calculations, and taking into account temperature and pressure, afford a comprehensive picture of the behavior and interaction of oxygen and Ag(111), and provides valuable insight into the function of silver as an oxidation catalyst. The obtained phase diagram reveals the most stable species present in a given environment and thus identifies (and excludes) possibly active oxygen species. In particular, for the conditions of ethylene epoxidation, a thin oxidelike structure is most stable, suggesting that such atomic O species are actuating the catalysis, in contrast to hitherto proposed molecularlike species.