The Role of Preadsorbed Atomic Hydrogen in the NO Dissociation on a Zigzag Stepped Gold Surface: A DFT Study
The Role of Preadsorbed Atomic Hydrogen in the NO Dissociation on a Zigzag Stepped Gold Surface: A DFT Study
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DOI：
10.1021/jp901266g
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发表时间：
2009-04
影响因子：
3.7
通讯作者：
José L. C. Fajín;M. Cordeiro;J. R. Gomes
中科院分区：
文献类型：
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作者：
José L. C. Fajín;M. Cordeiro;J. R. Gomes
采用密度泛函理论和周期性超原胞方法研究了Au（321）表面存在和不存在氢时NO的解离.氢在NO解离反应中的作用通过比较四种不同的途径（即在清洁表面上直接解离NO和在N-O键断裂之前与氢吸附原子反应的途径）来研究。在后一种情况下，考虑通过NOH中间体的两种途径，产生N* + OH* 或N* + H2O*，还考虑通过NHOH中间体的另一种途径，产生NH* 和OH* 物质。计算预测，动力学上最有利的途径是产生氮吸附原子和水，即，NO* +2 H * → N* + H2O* 通过NOH* 中间体。该反应是放热的（1.1eV），并且单独的NO* + H* → NOH* 和NOH* + H* → N* + H2O* 反应的能垒是1.05eV。计算了氢分子解离反应的能垒。
NO dissociation with and without the presence of hydrogen on the Au(321) surface was investigated using density functional theory and a periodic supercell approach. The role of hydrogen in the reaction of NO dissociation is studied by comparing four different routes (i.e. direct dissociation of NO on the clean surface and paths involving reaction with hydrogen adatoms prior to N−O bond cleavage). In the latter situation, two routes via a NOH intermediate were considered, producing N* + OH* or N* + H2O*, and another route via a NHOH intermediate was also considered, yielding NH* and OH* species. The calculations predict that the kinetically most favorable route is that producing nitrogen adatoms and water, i.e., NO* + 2H* → N* + H2O* via the NOH* intermediate. This reaction is exothermic (1.1 eV) and the energy barriers for the separate NO* + H* → NOH* and NOH* + H* → N* + H2O* reactions are ∼0.5 eV. An identical energy barrier was calculated for the reaction of the dissociation of molecular hydrogen on th...