Bimetallic molybdenum-tungsten carbide/reduced graphene oxide hybrid promoted Pt catalyst with enhanced electrocatalytic activity and stability for direct methanol fuel cells

The commercial progress of direct methanol fuel cells (DMFCs) requires maximizing the utilization of expensive platinum (Pt) -group metals by explore a suitable support with desirable co-catalytic activity. In this study, a ternary hybrid electrocatalyst consisting of Pt nanoparticles supported on highly dispersed and well-defined bimetallic molybdenum-tungsten carbide (MoWC) nanocrystals incorporated reduced graphene oxide (rGO) is developed for efficient methanol oxidation reaction (MOR) and oxygen reduction reaction (ORR) in DMFCs. Various characterizations reveal that the combination of MoWC/rGO composite support with Pt nanoparticles, endows the ternary hybrid electrocatalyst within large specific surface area, more exposed active sites, excellent charge transfer property, as well as strong electronic coupling effect of Pt, MoWC, and rGO. Benefited from these merits, the optimized Pt/MoWC/rGO catalyst displays a significantly enhanced performance for MOR and ORR in both acidic and alkaline media. It shows higher mass and area activity of 1486.1/641.7 mA·mg−1Pt and 60.11/25.94 mA·cm−2, larger onset and half-wave potentials of 1.12/1.02 and 0.88/0.90 mV in acidic/alkaline electrolytes, as well as outstanding stability and anti-poisoning ability, compared to those of Pt supported on other supports containing Vulcan XC-72 carbon black.