Theoretical study of adsorption and dissociation of NH_3 on the Ir{110}(1×2) surface  

作　　者：HUANG WuYing XIE DaiQian 

机构地区：[1]Key Laboratory of Mesoscopic Chemistry, Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China

出　　处：《Chinese Science Bulletin》2008年第20期3169-3172,共4页

基　　金：the National Natural Science Foundation of China (Grant Nos. 20725312 and 20533060);National Basic Research Program of China (Grant No. 2007CB815201)

摘　　要：The adsorption and dissociation of NH3 on Ir{110}(1×2) have been investigated using the densityfunctional calculations at a coverage of 0.25 ML. The adsorption sites, energy, and geometries were obtained for NH3, NH2, and H adsorptions on the surface. The transition state for NH3 dissociation on Ir{110}(1×2) was also identified. It was found that NH3 is adsorbed preferentially at the ridge atop site, while NH2 and H are adsorbed at the ridge bridge site. The activation barrier of NH3 dissociation is 78.4 kJ/mol, which is very close to the NH3 adsorption energy of 90.0 kJ/mol. This indicates that the desorption and dissociation of NH3 on Ir{110}(1×2) are very competitive, which is consistent with the recent experimental results.The adsorption and dissociation of NH3 on Ir{110}（1×2） have been investigated using the density- functional calculations at a coverage of 0.25 ML. The adsorption sites, energy, and geometries were obtained for NH3, NH2, and H adsorptions on the surface. The transition state for NH3 dissociation on Ir{110}（1×2） was also identified. It was found that NH3 is adsorbed preferentially at the ridge atop site, while NH2 and H are adsorbed at the ridge bridge site. The activation barrier of NH3 dissociation is 78.4 kJ/mol, which is very close to the NH3 adsorption energy of 90.0 kJ/mol. This indicates that the desorption and dissociation of NH3 on Ir{110}（1×2） are very competitive, which is consistent with the recent experimental results.

关 键 词：氨气 铱 吸附 分裂 密度泛函理论 跃迁态 

分 类 号：O647.3[理学—物理化学]