Trimetallic non-noble NiCoSn alloy as an efficient electrocatalyst towards methanol oxidation and oxygen reduction reactions

Abstract

The development of a non-noble, highly efficient bifunctional catalyst for methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) is the bottleneck in the alkaline direct methanol fuel cells (ADMFC). Ni-based bi/tri metallic alloys are the promising candidates next to the noble metals in the alkaline medium.Herein we present a facile hydrazine-assisted hydrothermal technique to synthesize a trimetallic nickel-cobalt-tin (NiCoSn) alloy as an efficient electrocatalyst for MOR and ORR reactions. The physiochemical analysis confirms the formation of trimetallic alloys with a high surface area. The as-synthesized trimetallic NiCoSn electrocatalyst exhibited superior MOR activity in terms of mass activity (509 mA mg−1 at 1.55 V vs RHE) and stability than the bimetallic alloys in 1.0 M KOH electrolyte. Further, the trimetallic alloy delivered a lower onset and half-wave potential of 0.8 and 0.72 V vs RHE with the favorable four-electron transfer in the oxygen reduction reactions. This work highlights a facile approach for preparing Ni-based trimetallic alloys as a promising candidate for the alkaline direct methanol fuel cells/other catalytic applications.