CARBON PARTICLE HAVING DEPOSITED FINE PARTICLES, PROCESS FOR PRODUCING THE SAME, AND ELECTRODE FOR FUEL CELL

摘要

Carbon particles having fine particles deposited thereon which can be used as a substitute for the carbon particles having platinum deposited thereon and metallic platinum particles which are presently in general use as, e.g., a catalyst for electrodes in fuel cells. Compared to the conventional carbon particles having platinum deposited thereon, etc., the carbon particles are effective in greatly reducing the amount of platinum to be used. The carbon particles are characterized by comprising carbon particles and, deposited on the surface of the carbon particles, fine particles of a perovskite type composite metal oxide in each of which fine noble-metal particles are present throughout the whole particle. Also provided is a process for producing the carbon particles. The carbon particles having deposited fine particles have a constitution in which fine particles of a perovskite type composite metal oxide each having fine noble-metal particles present throughout the whole perovskite type oxide particle and having a crystallite size of 1-20 nm are deposited on carbon particles. The process for producing such carbon particles having fine particles deposited thereon comprises preparing a solution containing fine perovskite type composite oxide particles and complex ions of a metal for constituting fine noble-metal particles, subsequently repeating the step of impregnating the solution into carbon particles and dried the particles to thereby adsorb complex ions of the metal onto the carbon particles, and then subjecting the resultant particles to heat treatment.