Promotion of palladium catalysis by silver for ethanol electro-oxidation in alkaline electrolyte

Bimetallic PdmAg alloy nanostructures (m being the atomic Pd/Ag ratio, m = 0.1–1.5), prepared through a simple co-reduction process, are employed as the catalysts toward ethanol electro-oxidation reaction (EOR). XPS results show that the electronic structure of Pd can be modified due to the presence of Ag, which is crucial for the enhancement of the catalytic performance of the PdmAg/C catalysts. It is found that the catalytic activity of Pd was strongly dependent on the composition of the PdmAg/C catalysts, with the best performance found with the Pd0.5Ag/C. The mass-specific activity (MSA) and intrinsic activity (IA) data of Pd0.5Ag/C is 3.6 and 2.4 times higher than that of the monometallic Pd/C catalyst, respectively, which might be ascribed to the electronic and synergistic effect. These findings would be promising in understanding the mechanism of EOR on Pd-based catalysts and designing the bimetallic catalysts for direct ethanol fuel cells and other applications.