Insight into the Structures and Electrocatalytic Activities of PdAg Alloy on RGO in the Oxidation of Ethanol, Ethylene Glycol and Glycerol

The biorenewable alcohols are identified as the promising energy in fuel cells, but the lack of efficient catalysts limits the electricity output. Here, we chemically grew the PdAg alloy nanoparticles (NPs) on reduced graphene oxide (RGO) to obtain PdxAgy(m)/RGO, and investigated the dependences of peak current densities on the metal loadings (m), Pd mole fractions (x), and sizes. The maximal peak currents of 1.86, 4.88, 14.3 and 13.6 × 104 mA cm−2 mgPd−1 were respectively achieved in the electrooxidation reactions of methanol, ethanol, ethylene glycol and glycerol. It is shown that the interactions of PdAg NPs with RGO can control the catalytic efficiencies through mediating the electronic characteristics of metal NPs and the reactant absorptions. Except the catalysts for methanol oxidation reaction, the efficient catalysis possesses the same lattice structure in PdAg alloys with the optimized m, and gives a common descriptor to select the catalyst with high catalytic activity.