Aqueous Phase Approach to Au-Modified Pt-Co/C toward Efficient and Durable Cathode Catalyst of PEMFCs

The commercialization of proton exchange membrane fuel cells (PEMFCs) calls for the development of active and durable Pt-based catalysts for oxygen reduction reaction (ORR) by means of a cost-effective and environmentally benign protocol. We report herein an all aqueous phase preparation of carbon supported Au-modified Pt-Co alloy catalyst (Au/PtCo/C), which involves the dimethylamine borane co-reduction of aqueous Pt(II) and Co(II) precursors to form a Pt-Co/C catalyst and the ethanol reduction of an aqueous Au(III) precursor to form Au/Pt-Co/C. This Au/PtCo/C catalyst not only shows a greatly enhanced ORR activity like the homemade Pt-Co/C and state-of-art Pt-Co/C(com) catalysts as compared to the Pt/C catalyst but also exhibits a much higher durability over the Pt/ C(com), homemade Pt-Co/C, and state-of-art Pt-Co/C(com) catalysts in accelerated degradation tests (ADTs) with both half-cell and single-cell configurations. Specifically, the maximum power density of a PEMFC involving the Au/Pt-Co/C cathode suffers only a 6% loss after 30 000 cycles of a standard ADT while that involving the state-of-art Pt-Co/C(com) suffers a 37% loss. This research provides an alternative route to prepare efficient and durable Pt-based ORR catalysts toward a widespread application of PEMFCs.