PtnCum(n+m=4) 对甲醇第一步脱氢催化性能的理论研究

Pt_nCu_m(n+m=4) 对甲醇第一步脱氢催化性能的理论研究

摘要: 采用密度泛函理论（DFT）中的B3PW91/LANL2DZ（ECP）方法在Gaussian09程序包中计算了二元合金催化剂Pt_nCu_m（n+m=4）催化甲醇第一步脱氢反应的相关几何参数，主要研究了Pt_nCu_m（n+m=4）在甲醇分子表面的吸附和脱氢反应的机理。通过比较E_ads和脱氢能垒等发现，Pt_nCu_m（n+m=4）催化甲醇脱氢的最优反应路径为甲醇分子中的甲基氢吸附在该二元金属催化剂Pt位点上导致的C-H断裂。并对比了Pt_nCu_m（n+m=4）中Pt与Cu比例对甲醇催化脱氢活性的影响，结果表明，当二元合金催化剂中Pt与Cu的比例为1：1时，催化活性最高。

Abstract: The B3PW91/LANL2DZ (ECP) method has been used to calculate the geometric parameters of adsorption and dehydrogenation of methanol on Pt_nCu_m(n+m=4). All the calculations have been used the Gaussian09 program package. Compared the adsorption energy with dehydrogenation energy barrier, it can be concluded that the path of the adsorption of methyl on the Pt site and the C-H broken is the most favorable reaction in all of the possible paths. When the catalyst of Pt_nCu_m (n+m=4) have different Pt and Cu proportions we find the catalytic activity is the best with the Pt and Cu ratio of 1:1.