Rough-surfaced bimetallic copper-palladium alloy multicubes as highly bifunctional electrocatalysts for formic acid oxidation and oxygen reduction

Engineering the morphology of nanomaterials and modifying their electronic structure are effective ways to improve their performance in electrocatalysis. Through combining the co-reduction of Pd2+ and Cu2+ precursors with a digestive ripening process in oleylamine, we report the synthesis of copper-palladium (Cu-Pd) alloy multicubes with rough surfaces. Benefiting from their alloy and unique rough-surfaced structure, which provides ample edge/corner and step atoms as well as the electronic coupling between Cu and Pd leading to the lower of d-band center, the rough-surfaced Cu-Pd alloy multicubes show much better electrocatalytic performance not only for formic acid oxidation but also for oxygen reduction in comparison with those of spherical Cu-Pd alloy nanoparticles and commercial Pd/C catalyst. In contrast, we confirm that the rough-surfaced Cu-Pd alloy multicubes only exhibit very low Faradaic efficiency (34.3%) for electrocatalytic conversion of carbon dioxide (CO2) to carbon monoxide (CO) due to the presence of strong competing hydrogen evolution reaction, which results in their very poor selectivity for the reduction of CO2 to CO. The findings in this study not only offer a promising strategy to produce highly effective electrocatalysts for direct formic acid fuel cells, but also enlighten the ideas to design efficient electrocatalysts for CO2 reduction. (C) 2018, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V