Membrane electrode assembly (MEA) is a key part determining the electrochemical performance of polymer electrolyte membrane fuel cell (PEMFC).[1] MEA consists of catalyst layer, gas diffusion layer and polymer electrolyte. Among them, catalyst layers can influence resistance caused from the limitation of reduction and oxidation reactions, and gas diffusion.[2] Catalyst coating methods control those electrochemical resistances, which are catalyst activity, ohmic resistance and mass transport overpotential, changing structures and morphology of catalyst layers with no variables of the amount of Nafion?
