(509l) Effect Of Solvent In The Sol-Gel Preparation Of Platinum-Carbon Aerogel Catalysts For Pemfc

Carbon-supported platinum catalysts have been prepared by various techniques, such as impregnation, ion exchange, precipitation and colloidal method. Recently, particular attention has been paid to carbon aerogels as catalyst support for fuel cell applications. Carbon aerogels have unique properties such as high conductivity, pronounced mesoporosity, high surface area and relatively low degree of microporosity that can make them more suitable electrocatalyst support than other types of carbons. Platinum-organic composite aerogels were prepared from the alcoholic sol-gel reaction of organic precursors using propylene oxide as a primary particle formation agent from platinum salt and followed by supercritical drying with carbon dioxide. Subsequent carbonization of platinum-organic aerogels under a reducing gas flow produced platinum-carbon aerogels. Electrochemical properties of various platinum-carbon catalysts were measured by cyclic voltammetry with adsorption and desorption of CO on the platinum surface. The surface and morphology of the platinum-carbon catalysts were characterized by XPS and TEM. The catalytic properties of the resultant platinum-carbon aerogels were highly dependent on the alcohol solvent type in the sol-gel preparation. The initial electrochemical active surface (EAS) area of the aerogel catalysts increased in the following order: primary > secondary > tertiary.