Cu- and Co-Modified Pd/C Nanoparticles as the High Performance Cathodic Catalysts for Mg-H2O2 Semi-Fuel Cell

We had prepared PdxCoy/C and PdxCuy/C nanocatalysts with different actomic ratio of Pd and Co or Cu via modified sodium borohydride reduction method and investigated their electrocatalytic properties for hydrogen peroxide (H2O2) reduction reaction with emphases on the effects of composition and structure. The activities of PdxCoy/C and PdxCuy/C catalysts increased firstly and then decreased with the amount of Pd adding. Both the Pd8Co/C and Pd8Cu/C showed the better catalytic performance than that of the other Pd and Co or Cu atomic ratio. The Pd8Co and Pd8Cu NPs were 3–4 nm in size and uniformly distributed on the C surface in an alloy way. The Pd8Co/C and Pd8Cu/C catalysts exhibited a superior activity and stability on H2O2 electroreduction reaction than the Pd/C and the commercial Pd/C (JM) catalysts, which due to Co and Cu enter into the Pd lattice and alter the electronic structure of Pd. The Mg-H2O2 semi-fuel cells with the two catalysts supported on the carbon paper as the cathodes expressed a peak power density of 140 mW cm−2 for the Pd8Co/C cathode and 168 mW cm−2 for the Pd8Cu/C cathode.