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HCOOH在Pd(111)表面top,fcc,hcp,bridge四个吸附位和Pd-Fe(111)表面Pd-top,Fe-top,PdPd-bridge,PdFe-bridge,FeFe-bridge,Pd2Fehcp,PdFe2-hcp,Pd2Fe-fcc,PdFe2-fcc等9个吸附位的13种吸附模型进行了能量计算、构型优化,得到了HCOOH较有利的吸附位;并对清洁表面进行能带分析.结果表明:掺杂Fe后,Pd催化剂对HCOOH催化活性增强;HCOOH在Pd(111)表面的最稳定吸附位fcc的吸附能是-41.8kJ·mol-1,在Pd-Fe(111)表面的最稳定吸附位Pd2Fe-hcp的吸附能是-126.5kJ·mol-1,而且HCOOH在金属表面属于化学吸附.
The density functional theory（DFT） and periodic slab model are used to investigate Formic acid adsorption on Pd（111） and Pd-Fe（111） surfaces. The adsorption energies, equilibrium geometries of Formic acidon four possible sites（top,fcc, hcp, and bridge） on Pd（111） surface and on nine possible sites（Pd-top, Fe-top, PdPd-bridge, PdFe-bridge, FeFe-bridge, Pd2Fe-hcp, PdFe2-hcp, Pd2Fe-fcc, Pd- Fe2-fcc） on Pd-Fe（111） surface are predicted and compared. The relatively favorable adsorption sites are found. Band structures of the clean Pd（111） and Pd-Fe（111） surfaces and density of states analysis of the most stable sites are discussed. The results reveal that the range of energy band for Iron-doped Pd （111） surface are enhanced and the activity of catalyst are improved; the adsorption energy for Formic acid adsorption on the most stable sites on Pd（111） and Pd-Fe（111） surfaces are --41.8 and --126.5 kJ . mol-1, respectively. The calculated results show that there are chemical bonds between formic acid and Pd（111）, Pd-Fc（111） surface, respectively.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2014年第1期161-166,共6页
Journal of Atomic and Molecular Physics
基金
重庆市教委科学技术资助项目(KJ121320
KJ131318)
