【摘要】 采用密度泛函理论与周期性平板模型相结合的方法,对NO在Rh(111)表面top、fcc、hcp、bridge4个吸附位和Rh-Pt(111)表面Rh-top、Pt-top、RhRh-bridge、Rh Pt-bridge、Pt Pt-bridge、Rh2Pt-hcp、Rh Pt2-hcp、Rh2Pt-fcc、Rh Pt2-fcc 9个吸附位的13种吸附模型进行了构型优化、能量计算,得到了NO较有利的吸附位;并对最佳吸附位进行总态密度分析.结果表明:NO在Rh(111)和Rh-Pt(111)表面的最稳定吸附位分别为Rh-top和Pt-top位,其吸附能的大小顺序为Ph(111)<Rh-Pt(111);NO与金属表面成键,属于化学吸附.更多还原

【Abstract】 The density functional theory( DFT) and periodic slab model have been used to investigate NO adsorption on Rh( 111)and Rh-Pt( 111) surfaces. The adsorption energies,equilibrium geometries of NO on four possible sites( top,fcc,hcp,and bridge) on Rh( 111) surface and on 9 possible sites [Rh-top,Pt-top,RhRh-bridge,Rh Pt-bridge,Pt Pt-bridge,Rh2Pt-hcp,Rh Pt2-hcp,Rh2 Ptfcc,Rh Pt2-fcc]on Rh-Pt( 111) surface have been predicted and compared. The relatively favorable adsorption sites have been found.Density of states analysis of the most stable sites have been discussed. The results reveal that the most stable sites for NO adsorption on Rh( 111) and Rh-Pt( 111) surfaces are Rh-top and Pt-top,respectively; the order of the adsorption energy on the most stable sites is Ph( 111) < Rh-Pt( 111). The calculated results show that there are chemical bonds between NO and Rh( 111),Rh-Pt( 111) surface,respectively.更多还原