Co-electrodeposited Mesoporous PtM (M=Co, Ni, Cu) as an Active Catalyst for Oxygen Reduction Reaction in a Polymer Electrolyte Membrane Fuel Cell

Abstract

Mesoporous thin films of PtCo, PtNi and PtCu are prepared by a single-step potentiostatic electrodeposition on a carbon substrate. Films are characterized by SEM, XRD, XRF and BET, and their activity for oxygen reduction reaction (ORR) is studied in an acidic three-electrode cell. The results are compared with both a commercial nanoparticle Pt/C catalyst and a Pt catalyst prepared using the same method. Additionally, the ORR activity of PtCo is studied in a fuel cell. The onset potential of ORR is found to be higher for all the electrodeposited catalysts compared to commercial Pt/C. The ORR activity of mesoporous Pt is found to be linearly dependent on the amount of deposited platinum within a platinum loading range of 0.1-0.5 mg cm-2. All the mesoporous catalysts exhibited higher mass activity towards ORR than commercial Pt/C. Of the studied catalysts, PtCo is found to have the highest durability. Similar results are obtained in fuel cell experiments as PtCo exhibits enhanced durability and activity towards ORR, peak powers being 60, 70 and 90 mWgPt-1 for commercial Pt/C, mesoporous Pt and mesoporous PtCo, respectively.