Preparation of Nano-Structured Catalyst Layers on Nafion® Membrane by Electrophoretic Deposition

Abstract

A membrane electrode assembly (MEA) was successfully prepared by electrophoretic deposition (EPD) process onto Nafion® 117 membrane. An ethanol suspension containing carbon powder with Pt catalyst and Nafion® ionomer was utilized to the EPD process. The catalyst layers fabricated by the EPD process were well-attached to both sides of the membrane and those thicknesses were easily controlled in a sub-micrometer scale by the EPD duration and applied electric field intensity. The obtained catalyst layer had uniform and porous structure compared to that prepared by a decal transfer process. This structure was favorable for fuel gas diffusion, resulting in improvement of Pt utilization up to 76%. Accordingly, the MEA prepared by the EPD process exhibited higher cell performance with half amount of Pt loading compared to the ordinary one.