Morphology-control and template-free fabrication of bimetallic Cu–Ni alloy rods for ethanol electro-oxidation in alkaline media

Abstract

Abstract The design of highly efficient and stable non-noble transition metal-based electrocatalysts for the ethanol oxidation reaction (EOR) is imperative for the development of the direct ethanol fuel cells (DEFCs). In this work, we report a simple template-free method for preparing a type of rod-like Cu–Ni alloy particle with the unique porous structure and evaluate it as the electrocatalyst for the EOR in alkaline media. The pH, which was adjusted by the addition of NH3·H2O during the liquid-phase coprecipitation process, was found to be a key factor to shape Cu–Ni alloy precursor into a quasi-one-dimensional morphology. After annealing at a reducing atmosphere (H2/Ar\xa0=\xa05/95, v/v), well-alloyed Cu–Ni rods with the predefined molar ratio (Cu/Ni) of 1:1, a specific surface area of 6.84\xa0m2\xa0g−1, and the average pore size of 30.97\xa0nm were obtained. Cyclic voltammetry (CV) and chronoamperometry (CA) test results show that the prepared Cu–Ni alloy catalyst demonstrated an anodic current peak of 86.10\xa0mA\xa0cm−2 in the presence of 0.2\xa0M ethanol and a 95% retention of current density after 2000\xa0s, indicating its good electrochemical performance in terms of catalytical activity and long-term stability. This bottom-up synthesis strategy would enrich the fabrication methodologies and open up a promising avenue for preparing multiple Ni-based EOR electrocatalysts with the easy-controllable morphologies and porous structure at the industrial scale.