一氧化氮在Cu_3Pt(111)表面的吸附行为  

Adsorption Behavior of NO on Cu_3Pt(111) Surface

作　　者：解秀娟[1] 陈文凯[1] 孙宝珍[1] 郭欣[2] 章永凡[1] 

机构地区：[1]福州大学化学系,福州350108 [2]华中科技大学煤燃烧国家重点实验室,武汉410074

出　　处：《物理化学学报》2010年第11期3047-3051,共5页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(90922022);华中科技大学煤燃烧国家重点实验室基金(FSKLCC0814);福建省高等学校新世纪优秀人才计划(HX2006-103;HX2006-98)~~

摘　　要：运用密度泛函理论中广义梯度近似(GGA)的PW91方法,结合周期性平板模型,探讨了NO分子在Cu3Pt(111)表面上不同吸附位的吸附行为.结果表明:NO分子以N端朝下方式吸附在top-Pt以及hcp1和fcc2位(分别为表面Cu2Pt和Cu3簇)的吸附模式最稳定,吸附能分别为101.8、124.5和118.1kJ·mol-1.对于hcp1和fcc2位的吸附,NO中的N原子分别与底物的Cu2Pt和Cu3簇成键.吸附前后的电荷布居、态密度和振动频率的分析结果表明,净电子从底物合金表面转移到NO,N—O键伸长,频率发生红移.合金Cu3Pt和纯贵金属Pt对NO的吸附性质相似.The adsorption behavior of NO onto a Cu3Pt （111） surface was studied using a periodic slab model and the PW91 generalized gradient approximation （GGA） within the framework of density functional theory. The calculated results indicated that NO adsorption with N-down on the top-Pt, hcp1, and fcc2 sites resulted in favorable structures with predicted adsorption energies of 101.8, 124.5, and 118.1 kJ·mol-1, respectively. For adsorption onto the hcp1 and fcc2 sites, N atom from NO formed bonds with Cu2Pt and Cu3 clusters, respectively. An analysis of the density of states, charge population, and vibrational frequencies before and after the adsorption showed that electrons transferred from the surface of the alloy to NO and that the N—O bond was elongated and its vibrational frequency was red- shifted. The Cu3Pt alloy and pure precious metal Pt have similar adsorption properties to NO.

关 键 词：密度泛函理论 一氧化氮 铂铜合金 吸附 

分 类 号：O647.32[理学—物理化学]