PtCu二元金属催化剂抗CO中毒性能的理论研究

基于密度泛函第一性原理研究了M-graphene(M=Pt,Cu,PtCu;graphene:pristine,Stonewales,Single-vacancy graphene)催化剂的抗CO中毒能力.对于纯Pt和纯Cu吸附在石墨烯上时,Pt的吸附能力最强,吸附结构最稳定.当Pt中掺杂Cu后,PtCu二元金属催化剂在石墨烯上的吸附结构的稳定性进一步增强.通过对M-graphene-CO吸附结构的研究,发现以缺陷石墨烯为载体的金属催化剂的抗CO中毒能力优于以原始石墨烯为载体的同种金属催化剂,PtCu二元金属催化剂抗CO中毒能力明显好于纯Pt和纯Cu的抗毒性.因此,缺陷石墨烯载体以及掺杂Cu的PtCu二元金属催化剂,对于提高催化剂的稳定性和抗CO中毒能力起到了重要的作用.

Theoretical study on the anti-CO poisoning by PtCu binary metal catalyst

The M-graphene catalysts (M = Pt, Cu and PtCu; graphene: pristine, Stone-wales, Single-vacancy graphene) for anti-CO poisoning have been learned by the first principles of density functional theory (DFT). For the pure Pt and Cu adsorbed on the graphene, the adsorption capacity of Pt is stronger and the adsorption structure of Pt-graphene is more stable. When Pt is doped by metal Cu, the stability of PtCu catalyst on graphene is stronger than Pt-graphene. By studying the adsorption structures of M-graphene-CO, it has been found that the metal catalysts with the defect graphene as the supporter are better than the pristine graphene in the anti-CO poisoning, and the Cu doped method will improve the tolerance of PtCu catalyst to CO poisoning. Therefore, we can modify the electrode catalyst in the direct methanol fuel cell (DMFC) by doping the non-noble metal Cu in the pure Pt with defect graphene supporter. The catalysts of PtCu-SW and PtCu-SV not only improve their ability to resist CO poisoning and catalysts stability, but also reduce the cost of Pt catalyst in the DMFC.