Water Production Reaction on Rh(110)

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• 作者：Cristina Africh ; Haiping Lin ; Martina Corso ; Friedrich Esch ; Renzo Rosei ; Werner A. Hofer ; and Giovanni Comelli
• 刊名：Journal of the American Chemical Society
• 出版年：2005
• 出版时间：August 17, 2005
• 年：2005
• 卷：127
• 期：32
• 页码：11454 - 11459
• 全文大小：483K
• 年卷期：v.127,no.32(August 17, 2005)
• ISSN：1520-5126

文摘

By means of scanning tunneling microscopy and density functional theory calculations, we studiedthe water formation reaction on the Rh(110) surface when exposing the (2 × 1)p2mg-O structure to molecularhydrogen, characterizing each of the structures that form on the surface during the reaction. First the reactionpropagates on the surface as a wave front, removing half of the initial oxygen atoms. The remaining 0.5monolayers of O atoms rearrange in pairs, forming a c(2 × 4) structure. Second, as the reaction proceeds,areas of an intermediate structure with c(2 × 2) symmetry appear and grow at the expense of the c(2 ×4) phase, involving all the oxygen atoms present on the surface. Afterward, the c(2 × 2) islands shrink,indicating that complete hydrogenation occurs at their edges, leaving behind a clean rhodium substrate.Two possible models for the c(2 × 2) structure, where not only the arrangement but also the chemicalidentity is different, are given. The first one is a mixed H + O structure, while the second one resemblesthe half-dissociated water layer already proposed on other metal surfaces. In both models, the high localoxygen coverage is achieved by the formation of a hexagonal network of hydrogen bonds.