Excellent electrocatalytic performance toward methanol oxidation of hierarchical porous NiCu obtained by electrochemical dealloying

In this work, the micro-nano hierarchical porous NiCu catalyst was synthesized by electrochemical dealloying of Zr70Ni15Cu15 (at %) metallic glass in 0.05 M hydrofluoric acid (HF) solution at 0.3 V for 1500 s (NPNC-1500). This hierarchical porous structure is characterized by unordered microcracks and nanoporous structure, which consists of uniform metallic nanoparticles and interconnected nanochannels. These nanoparticles, with a diameter size of 50–100 nm, exhibit the even-distributed chemical composition of Ni10.32Cu80.91O8.77 (at %). Compared with single nanoporous structure, the micro-nano hierarchical porous catalyst of NPNC-1500 showed much better catalytic activity toward methanol electrocatalytic oxidation in alkaline medium, as well as an excellent electrochemical stability. The enhanced electrocatalysis is mainly attributed to the abundant catalytic active sites and accelerated substance diffusion efficiency, deriving from the perfect micro-nano hierarchical porous structure. These results indicated a favorable application prospect of this cost-effective and high-performance porous catalyst in direct methanol fuel cells.