Dissociative chemisorption of CH4 on Ni(111)
Dissociative chemisorption of CH4 on Ni(111)
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DOI：
10.1063/1.462690
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发表时间：
1992-04
影响因子：
4.4
通讯作者：
Hong Yang;J. Whitten
中科院分区：
文献类型：
--
作者：
Hong Yang;J. Whitten
甲烷在镍（111）表面顶原子位置的解离化学吸附使用多电子嵌入理论来描述成键，将晶格模拟为41个原子的三层簇。从头算价轨道构型相互作用（多父）进行计算的局部表面区域允许在表面上的键合的准确描述。Ni 3d轨道被明确地包括在表面上的七个镍原子上。计算出CH 4吸附在顶部Ni位生成CH 3和H共吸附在分离的三重位的活化能为17 kcal/mol。CH_4分解为CH_3（ads）+H（ads）的过程为2.8kcal/mol的放热过程。Ni的3d轨道通过在解离过程中与甲烷的C-H轨道直接混合以及通过在过渡态的3d 9和3d 10构型的直接相互作用来贡献成键。讨论了吸附态CH_4和共吸附态CH_3与H的解离途径和成键性质。
The dissociative chemisorption of methane at an atop‐atom site on a (111) surface of nickel is treated using a many‐electron embedding theory to describe bonding, modeling the lattice as a 41‐atom, three layer cluster. Ab initio valence orbital configuration interaction (multiple parent) calculations carried out on a local surface region permit an accurate description of bonding at the surface. Ni 3d orbitals are explicitly included on seven nickel atoms on the surface. The calculated activation energy of CH4 adsorbed at an atop Ni site to produce CH3 and H coadsorbed at separated threefold sites is 17 kcal/mol. The dissociation of CH4 to CH3(ads)+H (ads) is predicted to be 2.8 kcal/mol exothermic. The Ni 3d orbitals contribute to the bonding by directly mixing with methane C–H orbitals during the dissociation process and through a direct interaction of 3d9 and 3d10 configurations at the transition state. The dissociation pathway and the bonding properties of adsorbed CH4 and coadsorbed CH3 and H are disc...