PEFC Electrocatalysts using Highly-Graphitized Mesoporous Carbon Supports

The electrocatalysts used in polymer electrolyte fuel cells (PEFCs) are subject to oxidative corrosion of the carbon catalyst support due to start-stop cycling, as well as aggregation of Pt nanoparticles due to load fluctuations. The use of mesoporous carbon (MC) as a catalyst support has previously been shown to suppress aggregation. In this study, highly graphitized MC is prepared as a catalyst support to suppress both carbon corrosion and aggregation in Pt/MC electrocatalysts. The effect of graphitization temperature on the catalytic performance is evaluated, as well as the effect of pretreatment via either ball milling or pulverization to achieve suitable particle size. The results indicate that the initial activity of the electrocatalysts is improved by graphitization of the MC support after milling, and that the graphitization step improves the start-stop cycle durability.