Preparation of ultra high loading supported Pt catalyst for direct methanol fuel cell

Abstract

Carbon-supported Pt catalysts with ultra high Pt loading up to 90 wt% for the DMFC cathode were prepared by novel polyol process, and characterized by XRD, TEM, and single cell performance of DMFC. Highly dispersed Pt particles on carbon support with 40-75 wt% metal loading could be obtained with ca. 3 nm Pt particles in a single reduction step by optimizing the synthesis parameters. Furthermore, ultra high Pt loading up to 85 wt% catalysts were prepared by multiple reduction of Pt precursors. Thus prepared catalysts exhibited stacked microstructure and the sizes of Pt particles were less than 5 nm. The single cell performances of the catalysts prepared by multiple reductions were superior to that of the catalysts prepared by single reduction, which are attributed to the stacking structure of Pt particles and thinner electrode by using high metal loading.