[Display omitted] • Highly dispersed and well-defined MoWC nanocrystals grown on rGO nanosheets by a hard template route. • Bimetallic MoWC/rGO nanohybrid displays a remarkable promotion effect to Pt electrocatalyst for both MOR and ORR in DMFCs. • The small-sized MoWC nanocrystals on rGO can largely increase the opportunity of MoWC to contact with the Pt catalyst for promoting the synergistic effect. • The function of rGO enhances the electron-transport property and allows the adsorbed oxygen rapidly permeates the Pt surface along the interfaces to form Pt-O ads. • More electron donation from bimetallic MoWC/rGO support to Pt boosts the interaction of each component. 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−1 Pt 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. [ABSTRACT FROM AUTHOR]