Ag nanoparticles anchored Ag2WO4 nanorods: An efficient methanol tolerant and durable Pt free electro-catalyst toward oxygen reduction reaction

Abstract

Oxygen reduction reaction is the most significant electrode reaction in electrochemical energy devices, such as fuel cells. State-of-the-art Pt/C catalysts possess certain drawbacks such as activity towards methanol oxidation, non-durability, and high cost. This has led to an extensive investigation on alternate catalysts that hold methanol tolerance, cost-effectiveness, and durability. Herein, we report the synthesis of Ag nanoparticle anchored Ag2WO4 nanorods and its application as a promising electro-catalyst towards oxygen reduction reaction (ORR) for the first time. The catalyst exhibits a higher current density with a more positive onset and half-wave potential than Ag/C and a comparable current density with commercial Pt/C in alkaline media. The synergic effect of a metal nanoparticle and mixed transition metal oxide is evident in the ORR activity, and it shows enhanced durability than the commercial Pt/C catalyst. Besides, it shows superior methanol tolerance by retaining its activity even after the addition of 1 M methanol, indicating appreciable selectivity towards ORR. Such a cost-effective, methanol tolerant, active, and durable catalyst has vital significance in the effective utilization of direct methanol fuel cell in commercial applications.