Direct chemical deposition of platinum on ionic conductive membranes and evaluation of the electrocatalytic activity

Direct chemical deposition of platinum at different polymer electrolyte membranes for a fuel cell application was studied. The developed method allows depositing platinum on acid and alkaline membranes. The depositions realized under different experimental conditions were characterized by RBS (Rutherford backscattering spectroscopy) and TEM (transmission electron microscopy) to determine the depth profile in the membranes and the mean size of platinum particles. The active surface area of the catalysts and the related particle size were characterized by cyclic voltammetry. Results indicated that a part of platinum was deposited inside the membrane. Roughness as high as 500 could however be achieved. Oxygen reduction reaction under working conditions close to those of a fuel cell cathode was studied to draw some kinetic data.