Cu‐ and Co‐Modified Pd/C Nanoparticles as the High Performance Cathodic Catalysts for Mg‐H 2 O 2 Semi‐Fuel Cell

We had prepared Pd x Co y /C and Pd x Cu y /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 (H 2 O 2 ) reduction reaction with emphases on the effects of composition and structure. The activities of Pd x Co y /C and Pd x Cu y /C catalysts increased firstly and then decreased with the amount of Pd adding. Both the Pd 8 Co/C and Pd 8 Cu/C showed the better catalytic performance than that of the other Pd and Co or Cu atomic ratio. The Pd 8 Co and Pd 8 Cu NPs were 3–4 nm in size and uniformly distributed on the C surface in an alloy way. The Pd 8 Co/C and Pd 8 Cu/C catalysts exhibited a superior activity and stability on H 2 O 2 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‐H 2 O 2 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 Pd 8 Co/C cathode and 168 mW cm −2 for the Pd 8 Cu/C cathode.