Pt Nanoparticles Dispersed on Ni/C Nanoflowers as Stable Electrocatalysts for Methanol Oxidation and Oxygen Reduction

Abstract

Improving the utilization of Pt by incorporating it in carbon-based materials is a feasible approach to overcome its disadvantages of low abundance and high cost for high-performance electrocatalysis. Herein, we propose a facile strategy to design a highly stable electrocatalyst of Pt–Ni/C by in situ loading Pt nanoparticles with a low ratio of 9.4 wt % onto the Ni/C support. Derived from Ni-based metal–organic frameworks (Ni-MOFs), the three-dimensional porous structure of Ni/C provides a large surface area and uniformly distributed Ni nanoparticles in carbon matrix to facilitate the formation and anchoring of Pt nanoparticles with good adhesion, ultrafine dispersion, and better stability. Benefiting from the good synergistic effect between Pt and Ni/C, this bifunctional Pt–Ni/C electrocatalyst shows outstanding stability toward both oxygen reduction and methanol oxidation reactions during the accelerated durability tests and exhibits improved activity nearly 2 times larger than that of commercial Pt/C. Moreover, the strategy is also employed to prepare different bifunctional electrocatalysts of Pd–Ni/C and Ru–Ni/C with satisfactory results. Therefore, the bifunctional electrocatalysts of M (Pt, Pd, Ru)–Ni/C developed from this in situ loading strategy are expected to be robust electrocatalysts for practical applications in direct methanol fuel cells.