High-Performance, Ultralow Platinum Membrane Electrode Assembly Fabricated by In Situ Deposition of a Pt Shell Layer on Carbon-Supported Pd Nanoparticles in the Catalyst Layer Using a Facile Pulse Electrodeposition Approach

An ultralow platinum loading membrane electrode assembly (MEA) is prepared by a facile synthesis process in which pulse electrodeposition is used to achieve a catalyst layer by the in situ decoration of carbon-supported Pd nanoparticles with a thin layer of Pt atoms. The novel MEA exhibits excellent performance in a H2/air single fuel cell, with Pt loading of as little as 0.015 mg cm–2 at the anode and 0.04 mg cm–2 at the cathode, outperforming the commercial Pt/C MEA (Johnson Matthey, 40 wt % Pt). The shift in binding energy of the XPS peak of Pd and Pt in the Pd@Pt/C MEA confirms the presence of the Pt shell and the interaction between the shell and the Pd core. We suggest that the high performance of this Pd@Pt/C MEA may be due to several factors: high Pt dispersion arising from the core–shell structure, high Pt utilization because there is no Nafion binder covering the Pt, the quantum effect caused by the high distribution of Pt, and the interaction between the Pt shell and the Pd in the core.