石墨烯基PtCu二元金属催化剂对甲醇吸附性能的理论研究

Theoretical study on methanol adsorption properties of graphene based PtCu catalyst

直接甲醇燃料电池作为最有潜力的能源越来越受到人们的关注.本文主要采用密度泛函理论(DFT),对石墨烯基PtCu催化剂吸附甲醇的结构进行了理论研究.通过分析甲醇吸附前后前线分子轨道、电荷和吸附能的变化,发现PtCu二元金属催化剂与甲醇相互作用中,甲醇容易吸附于Pt位点上.对于PtCu二元金属的Cu位点的吸附能力与纯Cu相比变化不大,但是PtCu二元金属的Pt位点相对于纯Pt催化剂对甲醇的吸附能力却有明显的提高.因此Cu的掺杂对于提高Pt位点的活性起到促进作用.

Direct methanol fuel cell has attracted more and more attentions as the most potential energy. In this paper, the density functional theory(DFT) was used to study the structure of methanol adsorbed on graphene based PtCu. By analyzing the changes of frontier molecular orbital, charge and adsorption energy, it is found that methanol is easily to adsorb on Pt site in the interaction between PtCu binary metal catalyst and methanol. The adsorption capacity of the Cu site of the PtCu binary metal does not change much compared with that of pure Cu, but the Pt site of the PtCu binary metal is significantly improved relative to that of pure Pt catalysts. Therefore, doped Cu plays a major role in improving the activity of Pt sites.