Effect of wetted graphene on the performance of Pt/PPy-graphene electrocatalyst for methanol electrooxidation in acid medium

摘要

Polypyrrole (PPy)-modified graphene can be used as a support of electrocatalyst in methanol oxidation reaction. In this paper, the Pt/PPy-graphene electrocatalyst is prepared through in situ synthetic method. The structure and electrochemical property of the electrocatalyst were investigated. The results show that the ultrathin water film between graphene and PPy was favorable as the PPy was distributed uniformly on the upper surface of graphene. The PPy-modified graphene enables the formation of Pt nanoparticles having a very narrow size profile centered around 8 nm and a very even spatial distribution on the graphene surface. The Pt/PPy-graphene catalyst exhibits a noticeably higher electrochemical activity in methanol oxidation reaction and performance durability than the Pt/graphene catalyst, and thus, PPy-graphene is a promising alternative catalyst support in direct methanol fuel cells.