The Research Of Pt-CeO₂/Graphene Used As DMFC Anode Catalyst

Direct methanol fuel cells(DMFCs) as a green power source, because of its higher energy density, use of liquid fuel(methanol), low operating cost, etc. shows great promise for practical application in transport and portable device applications. While the most effective Pt-based catalysts were limited by their low catalytic efficiency and carbon monoxide poisoning. In order to overcome the Pt-based catalyst’s defect, efforts have been devoted to developing a kind of Pt-Ce O2 composite. In previous studies, all of the Pt/Ce O2-based material are optimized empirically by tuning the scale of Ce O2 in the composite material, enhancing the interactions of Pt/Ce O2, changing the carbon-based supports or altering preparation conditions to achieve greater electrocatalytic activity. In this study, we attemp to improving the anti-poisoning by tuning the morphology/crystal form of Ce O2 and enhancing electrochemical performance by constructing a three-dimensional structure of Pt-Ce O2.In this study, we successfully synthesized of Ce O2 nanocrystals with different morphologies/crystal planes by self-assembly process. And we assembled them with graphene and Pt nanoparticle into Pt-x Ce O2/G by Na BH4 reduction. We performed a comparative study on the performance of the catalytic methanol electrooxidation, and found that the catalyst decorated by rod-shaped Ce O2(Pt-r Ce O2/Graphene) showed greatest catalytic performance and resistance to CO poisoning. Through the cyclic voltammograms characterization, Pt-r Ce O2/Graphene shows a minimum onset potential 0.152 V and highest If 286.7 m A/mg comparing to other Pt-x Ce O2/Graphene and Pt/Graphene. what’s more, Pt-r Ce O2/Graphene shows the highest If/Ib: 2.11 which means the greatest resistance to CO poisoning. It indicate that Pt-r Ce O2/Graphene shows significantly higher electrochemical activity and stronger ability of resistance to carbon monoxide poisoning compared with other materials.Furthermore, we successfully constructed a three-dimensional structure material of Pt-NRCe O2/Graphene by in-situ synthesis. Compared with other materials(Pt/Graphene、Pt-NRCe O2/Graphene),such design of the three-dimensional structure effectively improved the electrochemical properties of the catalyst. Through the cyclic voltammograms characterization, Pt-NRCe O2/Graphene shows the highest If(498 m A/mg) and have a maximum ESA: 72.6 m2/g. The standing current of Pt-NRCe O2/Graphene can remain at 30.5m A/mg after chronoamperometry test. It shows that such a design of the three-dimensional structure can effectively improve the electrochemical properties of the catalyst.