Wang W., Zhu M., Lu X., Gao Y., Li L., Cao Z., Li C., Liu J., Zheng H.
College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), South Africa
Wang, W., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Zhu, M., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Lu, X., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Gao, Y., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Li, L., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Cao, Z., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Li, C., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Liu, J., College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, China; Zheng, H., Materials Science and Manufacturing, Council for Scientific and Industrial Research (CSIR), South Africa
Oxygen storage capacity is influenced by the morphology and crystal-plane(s) of CeO<inf>2</inf>, which can thus affect the ability of this material to oxidise carbon monoxide. To investigate the effect of different morphologies/crystal-planes of CeO<inf>2</inf> on the electrocatalytic performance of DMFCs (Direct Methanol Fuel Cell), three different types of CeO<inf>2</inf> nanocrystals with different crystal-planes were synthesised and later assembled into Pt-xCeO<inf>2</inf>/Graphene composites with graphene and Pt nanoparticles as the electrocatalyst for DMFCs. According to the HRTEM images, the original morphology and crystal-plane structures of CeO<inf>2</inf> are essentially maintained in the three types of Pt-xCeO<inf>2</inf>/Graphene composite catalysts investigated in this work. The catalytic performance of the Pt-xCeO<inf>2</inf>/Graphene composites for methanol electrocatalytic oxidation was investigated by a series of electrochemical measurements. Compared with the other catalysts, Pt-rCeO<inf>2</inf>/Graphene demonstrates superior catalytic activity (onset potential: 0.15 V) and the strongest resistance to poisoning by carbonaceous species (I<inf>f</inf>/I<inf>b</inf>: 2.11). The results of H<inf>2</inf>-TPR shows that rCeO<inf>2</inf> with the {110} facet has the best surface reducibility among the xCeO<inf>2</inf> with different facets being investigated, which provides a rationale for the superior performance of the Pt-rCeO<inf>2</inf>/Graphene catalyst. This study indicates that metallic oxides with a suitable crystal plane and shape can effectively enhance the electrocatalytic performance of Pt-based catalysts for methanol electrooxidation. © The Royal Society of Chemistry 2015.