Influence of gas diffusion layer on Pt catalyst prepared by electrodeposition for proton exchange membrane fuel cells

The characteristics of a gas diffusion layer (GDL) including type of materials (carbon cloth and carbon paper), thickness, PTFE content and the presence of a micro porous layer of the GDL are found to influence the morphology and electrochemical active surface area of the Pt electrodeposited layer and fuel cell performance. The Pt particles deposited on carbon cloth are smaller than those deposited on carbon paper, but agglomerate in some areas. Despite their morphological differences, the Pt catalysts deposited on carbon cloth and carbon paper have relatively similar active surface area performance at 0.6 V. The Pt deposited on the very thin GDL, or on the GDL having high %PTFE or containing the micro porous layer consist of non-uniform particles distributed unevenly on the GDL surfaces, resulting in low active surface areas and performances. The Pt electrodeposition on the GDL containing the micro porous layer, however, can be improved by eliminating the hydrophobic sublayer in the post-treatment of GDL leading to the formation of smaller and more uniform particles with uniform distribution, resulting in increased active surface area and enhanced performance to the levels comparable to those obtained from non-micro porous layer GDL with suitable thickness and %PTFE.