Progress on the development of uniform distributed Pd electroless based catalysts on MEA for PEMFC application

Abstract

Envisaging the scale-up production of fuel cell electrodes, it was established an electrode manufacturing method that enables a uniform distribution of Pd-based catalyst over the MEA, ensuring simultaneously a low catalyst loading. The new procedure relies on the direct immobilization of the catalyst on the gas diffusion substrate by the electroless deposition after substrate activation by the electrodeposition of metal nucleus of Pd using the galvanostatic mode. The effect of the novel method on the catalyst distribution uniformity, morphology, and electrocatalytic activity towards the oxygen reduction reaction (ORR) in 0.1 M HClO₄ solution is compared to samples prepared by the conventional Sn/Pd sensitization—activation route. The performance of the PEMFC containing the same Pd load (0.09 mg cm⁻²) reveals to be slightly higher on depositing the Pd nucleus by the galvanostatic electrodeposition than by the conventional sensitization/activation method. The new method opens up new approaches to extend the electroless deposition to the preparation of a wide range of alloy catalysts for the cathode and anode sides of PEMFCs.