Design of 3D Hollow Porous Heterogeneous Nickel-Cobalt Phosphides for Synergistically Enhancing Catalytic Performance for Electrooxidation of Methanol.

Abstract

The synergistic effect among different components and the structural and morphological control of catalytic nanomaterials have attracted considerable research interest in the field of electrocatalysis, as using a rational design of the catalytic nanomaterials with the desired structure, morphology, and chemical compositions is an effective strategy for enhancing catalytic performance. Here, by changing the Ni/Co atomic ratio of raw materials, a series of samples with a three-dimensional (3D) hollow porous ternary multicomponent heterostructure has been successfully synthesized via a facile template-free solvothermal approach and subsequently annealing and phosphating treatments, and its formation mechanism is also investigated. By virtue of compositional and structural advantages, the optimized Ni1Co2Px (NiCoP/CoP/CoP2) nanoparticles show very high mass activity (436.9 mA mg-1) and area-specific activity (155 mA cm-2), as well as remarkable durability toward the methanol electrooxidation reaction (MOR) in alkaline solution. This catalytic activity is better than those of most of reported Ni/Co-based nonprecious metal catalysts. Particularly, a multicomponent synergistic effect on the MOR was observed. The present study not only provides a simple method for the fabrication of 3D hollow porous multicomponent composite nanomaterials, but also gives insights into the synergistic effect among the porous structure, chemical compositions, and catalytic activity of nanomaterials in the electrocatalytic oxidation of methanol.