Synthesis of Highly Porous Catalytic Layers for Polymer Electrolyte Fuel Cell Based on Carbon Aerogels

Abstract

Recent studies of the PEMFC catalytic layer electrocatalyst support showed that high surface area carbon blacks cannot be used efficiently (1) because they have necessarily small primary pores that yield high diffusion limitation for the oxygen reduction reaction (ORR). In the present paper, we first synthesized and characterized carbon aerogels which exhibit high surface area, high porous volume and adjustable pore-size distribution. In that way, they enable to decouple between surface area and porosity, while they are also promising electrocatalyst supports (2). Second, we elaborated new catalytic layers made from 2 different carbon aerogels with 2 different Nafion loadings. Finally, we characterized the structure of such catalytic layers, and evaluated their activity towards the oxygen reduction reaction (ORR). Finally, an appropriate catalyst support should display large pore-size and high surface area in order to reduce the PEMFC cathode platinum loadings without loosing activity, following the reduction of oxygen diffusion limitation.