Thermally driven interfacial diffusion synthesis of nitrogen-doped carbon confined trimetallic Pt3CoRu composites for the methanol oxidation reaction

Abstract

A current challenge to direct methanol fuel cells (DMFCs) is the insufficient electrocatalytic activity and anti-CO poisoning ability of Pt-based alloy catalysts toward the methanol oxidation reaction (MOR). In this work, a simple thermally driven interfacial diffusion alloying method is adopted to synthesize Pt₃CoRu/C@NC trimetallic nanoparticles (NPs) with enhanced MOR activity and anti-CO poisoning ability. The MOR mass activity of the Pt₃CoRu/C@NC catalyst (0.97 mA μg_Pt⁻¹) is 4.2 times larger than that of the commercial Pt/C catalyst (0.23 mA μg_Pt⁻¹). Moreover, the Pt₃CoRu/C@NC catalyst exhibits a much lower CO oxidation onset potential than the commercial Pt/C catalyst (0.35 V vs. 0.82 V), which directly indicates the improved anti-CO poisoning ability of the catalyst. This enhancement in MOR activity as well as anti-CO poisoning ability of the Pt₃CoRu/C@NC catalyst is mainly attributed to the synergistic effect of Ru (as a water activator) and Co (as an electronic modifier). Indeed, this work not only provides a satisfactory strategy for improving the activity and anti-CO poisoning ability of MOR electrocatalysts but also gives a significant insight into simple and cost-effective alloying methods for developing homogeneous trimetallic alloy catalysts.