论文部分内容阅读
采用DFT方法对CO在M(100)(M=Cu、Ag、Au、Pd、Pt)表面上的吸附行为进行了系统的比较性研究.结果表明,CO分子在这些过渡金属单晶表面上发生的是非解离性吸附,吸附后C-O键长都变长了,均不同程度地削弱了C-O键,继而活化了CO分子;从表面结合能、重叠集居数、轨道电子数变化等方面分析了成键强弱顺序,发现CO的吸附强度随Pd(100)、Pt(100)、Cu(100)、Ag(100)、Au(100)顺序依次减弱,并且将CO与过渡金属间的结合能(BE)、过渡金属的d电子转移数分别与水煤气变换反应活性数据进行了关联,在定性上比较好地解释了金属铜的催化活性优于其它金属的原因.
The adsorption behavior of CO on the surface of M (100) (M = Cu, Ag, Au, Pd, Pt) was studied systematically by DFT method.The results show that CO molecules occur on the surface of these transition metal single crystals Is non-dissociative adsorption, CO bond length becomes longer after adsorption, weakened CO bond to a certain extent, and then activated CO molecules; from the surface binding energy, the number of overlapping clusters, the number of orbital electrons were analyzed The results showed that the adsorption strength of CO decreased with the order of Pd (100), Pt (100), Cu (100), Ag (100) and Au (100) (BE), the number of d-electron transition of the transition metal is related to the water-gas shift reaction activity data, and the reason why the catalytic activity of copper metal is better than that of other metals is well explained qualitatively.