Te-template approach to fabricating ternary TeCuPt alloy nanowires with enhanced catalytic performance towards oxygen reduction reaction and methanol oxidation reaction†
Abstract
Fabricating ternary Pt-based alloys has emerged as a promising strategy to further enhance the catalytic performance of Pt catalysts in direct methanol fuel cells (DMFCs) for both the oxygen reduction reaction (ORR) and the methanol oxidation reaction (MOR). Herein, we reported for the first time the synthesis of ternary TeCuPt nanowires (NWs) by a Te-template-directed galvanic replacement reaction, in which Te NWs serve as both sacrificial templates and reducing agents. Compared with a binary TePt alloy and pure Pt catalysts, the ternary TeCuPt alloys exhibit a more positive half-wave potential and a higher specific area/mass activity for ORR, and also display a better CO tolerance ability and long-term stability for MOR. The enhanced catalytic performance for TeCuPt NWs is attributed to the electronic and geometric structure effects, originating from the Pt alloying with both Te and Cu components, which could weaken the binding strength between the Pt surface atoms and the intermediate species (e.g. OH*, CO*). Our studies have demonstrated a new alternative ternary Pt-based catalyst for both ORR and MOR, which could find application in DMFC.