Patent ID: 8273230

Claim:
A method for making a membrane fuel cell (MFC) electrode by low-voltage electrophoretic deposition (EPD) of carbon nanomaterial (CNM) supported catalyst comprising the steps of: providing an aqueous cathode EPD suspension via mixing an ionomer solution with electrolyte; providing an aqueous anode EPD suspension which is different from said aqueous cathode EPD suspension, via mixing a CNM-supported nanocatalyst with a solution of the same composition as that of the cathode EPD suspension, wherein a dry ratio of the CNM-supported nanocatalyst to the ionomer is 1:10 to 1:4 and wherein the CNM-supported nanocatalyst comprises 10 to 90 wt %; executing ultrasonication before and then, separately, high-speed stirring on both the cathode EPD suspension and the anode EPD suspension, respectively, thus turning them into catalyst/ionomer composites and homogenous suspensions; providing a low-voltage EPD apparatus with a porous membrane arranged to divide the low-voltage EPD apparatus into an anode compartment and a separate cathode compartment; filling the anode and cathode EPD suspensions in the anode compartment and cathode compartment, respectively such that the porous membrane inhibits mixing of generated gases with one another; introducing an inert gas into the anode compartment for stirring the anode EPD suspension and inhibiting formation of precipitation of the anode EPD suspension; providing an electrode base substrate selected from the group consisting of non-catalyzed gas diffusion electrode, carbon paper and carbon cloth as the anode and a platinum mesh as the cathode in the EPD apparatus; providing a low-voltage DC power supply to provide less than 5 volts DC to the EPD apparatus to evenly coat the composite of the CNM-supported nanocatalyst and the ionomer so as to form a catalyst layer on the electrode base substrate; removing the substrate coated with the catalyst layer from the EPD apparatus; washing the catalyst layer coated on the electrode base substrate with de-ionized water; and drying the catalyst layer coated on the substrate, thus forming the MFC electrode.