Highly Branched Metal Alloy Networks with Superior Activities for the Methanol Oxidation Reaction

Three-dimensional (3D) interconnected metal alloy nanostructures possess superior catalytic performance owing to their advantageous characteristics, including improved catalytic activity, corrosion resistance, and stability. Hierarchically structured Ni-Cu alloys composed of 3D network-like microscopic branches with nanoscopic dendritic feelers on each branch were crafted by a facile and efficient hydrogen evolution-assisted electrodeposition approach. They were subsequently exploited for methanol electrooxidation in alkaline media. Among three hierarchically structured Ni-Cu alloys with different Ni/Cu ratios (Ni_0.25 Cu_0.75 , Ni_0.50 Cu_0.50 , and Ni_0.75 Cu_0.25 ), the Ni_0.75 Cu_0.25 electrode exhibited the fastest electrochemical response and highest electrocatalytic activity toward methanol oxidation. The markedly enhanced performance of Ni_0.75 Cu_0.25 eletrocatalyst can be attributed to its alloyed structure with the proper Ni/Cu ratio and a large number of active sites on the surface of hierarchical structures.