Methanol oxidation reaction (MOR) in anodes is one of the significant aspects of direct methanol fuel cells (DMFCs), which also plays a critical role in achieving a carbon-neutral economy. Designing and developing efficient, cost-effective, and durable non-Pt group metal-based methanol oxidation catalysts are highly desired, but a gap still remains. Herein, we report well-defined hierarchical NiZn x @CuO nanoarray architectures as active electrocatalysts for MOR, synthesized by combining thermal oxidation treatment and magnetron sputtering deposition through a brass mesh precursor. After systematically evaluating the electrocatalytic performance of NiZn x @CuO nanoarray catalysts with different preparation conditions, we found that the NiZn1000@CuO (thermally oxidized at 500 °C for 2 h, nominal thickness of the NiZn alloy film is 1000 nm) electrode delivers a high current density of 449.3 mA cm–2 at 0.8 V for MOR in alkaline media as well as excellent operation stability (92% retention after 12 h). These outstanding MOR performances can be attributed to the hierarchical well-defined structure that can not only render abundant active sites and a synergistic effect to enhance the electrocatalytic activity but also can effectively facilitate mass and electron transport. More importantly, we found that partial Zn atoms could leach from the NiZn alloy, resulting in rough surface nanorods, which would further increase the specific surface area. These results indicate that the NiZn1000@CuO nanoarray architecture could be a promising Pt group metal alternative as an efficient, cost-effective, and durable anode catalyst for DMFCs.

nanoporous CuAg (NPCuAg) alloy catalysts with various Cu/Ag ratios are prepared by electrochemical dealloying of metallic glassy (MG) precursors. All dealloyed samples exhibit homogenous nanoporous structure and element composition distribution. After systematically evaluating their electrocatalytic performance toward MOR, it was found that the catalytic activity of the NPCuAg catalysts is enhanced along with the increase of Cu/Ag ratio, which may be attributed to the more exposed active reaction sites derived from high surface area of nanoporous structure and the optimal synergistic effect. Thus, the NPCu 1.75 Ag alloy catalyst presents the best methanol electro-oxidation properties, including a high current density of 397.2 mA cm À 2 and good operation stability that retaining 84.5 % catalytic activity even after 7200 s. These results outperform most reported copper-based MOR catalysts in alkaline methanol solution. Considering these advantages, the designed electrodes are expected to be promising catalysts for alkaline DMFCs applications.