The present state-of-art Proton Exchange Membrane Fuel Cell (PEMFC) technology is based on platinum (Pt) as a catalyst for both the fuel (anode) and air (cathode) electrodes. This catalyst is highly active but susceptible to poisoning by CO, which may be present in the H(sub 2)-fuel used or may be introduced during the fuel processing. Presence of trace amount of CO and H(sub 2)S in the H(sub 2)-fuel poisons the anode irreversibly and decreases the performance of the PEMFCs. In an effort to reduce the Pt-loading and improve the PEMFC performance, we propose to synthesize a number of Pt-based binary, ternary, and quaternary electrocatalysts using Ru, Mo, Ir, Ni, and Co as a substitute for Pt. By fine-tuning the metal loadings and compositions of candidate electrocatalysts, we plan to minimize the cost and optimize the catalyst activity and performance in PEMFC. The feasibility of the novel electrocatalysts will be demonstrated in the proposed effort with gas phase CO and H(sub 2)S concentrations typical of those found in reformed fuel gas with coal/natural gas/methanol feedstocks. During this reporting period several bi-metallic electrocatalysts were synthesized using ultra-sonication. These catalysts (Pt/Ru, Pt/Mo and Pt/Ir) were tested in MEAs. From Galvonstatic study the catalytic activity was found in the order of: Pt/Ru/C > Pt/Mo/C > Pt/Ir/C. It appears that electrocatalysts prepared by ultra-sonication process are more active compared to the conventional technique. Work is in progress to further study these catalysts for CO-tolerance in PEMFC and identify potential candidate metals for synthesis of tri-metallic electrocatalysts.
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