物理化学学报Issue(3)：425-434,10.DOI:10.3866/PKU.WHXB201501191
纳米团簇Au19Pd和Au19Pt催化解离N2O
Nitrous Oxide Decomposition Catalyzed by Au19Pd and Au19Pt Clusters
摘要
Abstract
The catalytic decomposition of N2O using Au19Pd and Au19Pt clusters as catalysts with optimized geometries was studied using density functional theory (DFT). The optimized geometries of the Au19Pd and Au19Pt clusters were obtained as a function of structural and thermodynamic analyses, in which the heteroatoms are on the surfaces of the clusters. We selected the Au19Pd cluster as a model cluster to investigate the reaction mechanism of N2O decomposition. There are two reaction pathways to be considered:Eley-Rideal (ER) and Langmuir-Hinshelwood (LH). We found that the first N2O decomposition needs to surmount an energy barrier of 1.118 eV, and is exothermic by 0.371 eV. The elimination of the residual oxygen atom on the surface has an energy barrier of 1.920 eV along the ER pathway after N2 desorption, which is higher than that along the LH channel (1.669 eV). The adsorption energy of the oxygen atom on the surface is-3.203 eV, and the oxygen atom diffusion on the surface needs to surmount an energy barrier of 0.113 eV along the LH pathway. This indicates that the oxygen atom is prone to transfer on the cluster to promote the generation of the O2 molecule, and therefore the LH is the optimized reaction pathway. We investigated the catalytic activity of Au19Pt for N2O decomposition along the LH pathway in comparison with the Au19Pd cluster. Both platinum and pal adium have catalytic activities for N2O decomposition, especial y the pal adium in this study. Comparison between this work and the theoretical study on periodic systems shows that these two clusters can be used as better catalysts for N2O decomposition, especial y the Au19Pd cluster. Furthermore, the O2 desorption is no longer the main barrier to the reaction, which further enhances the catalytic activities of these two clusters for N2O decomposition.关键词
纳米团簇/催化活性/N2O解离/反应机理Key words
Nanocluster/Catalytic activity/N2O decomposition/Reaction mechanism分类
化学化工引用本文复制引用
俞炜铃,左会文,陆春海,李奕,章永凡,陈文凯..纳米团簇Au19Pd和Au19Pt催化解离N2O[J].物理化学学报,2015,(3):425-434,10.基金项目
The project was supported by the National Natural Science Foundation of China (21203027) and Fujian Provincial Natural Science Foundation, China (2012J01041).国家自然科学基金(21203027)和福建省自然科学基金(2012J01041)资助项目 （21203027）
