Plasma-induced alloying as a green technology for synthesizing ternary nanoparticles with an early transition metal

•The plasma-induced alloying strategy facilitates the synthesis of multi-element alloy nanoparticle catalysts.•The presence of V in PtCo maximizes the oxygen reduction reaction activity of Pt.•It also improves the resistance of Pt and Co to oxidation or leaching under acidic environment.•The mechanism could improve functionality of proton exchange membrane fuel cells. [Display omitted] The strategy of employing Pt alloys with other transition metals (TMs) is advantageous owing to the enhancement of the oxygen reduction reaction (ORR) activity and the reduction of Pt usage. The ternary alloy system with early TMs can overcome stability issues and even enhance the intrinsic activity of the catalysts owing to rearrangement of electronic structures between three metal elements. Herein, efficient catalysts with V—an early TM—were successfully obtained via a plasma-induced alloying strategy. The effect of V in the PtCoV/C catalyst, which exhibits the highest ORR activity among the synthesized Pt–TM–V (TM = Co, Ni, Cu) catalysts, was determined. The addition of V induces electron rearrangement in PtCoV, inhibiting the oxidation of Co and V and optimizing the oxygen-binding energy of Pt. Thus, incorporation of V into PtCoV nanoparticles enhances the electrochemical ORR activity and stability. The catalytic performance of PtCoV achieved 966 mV of half-wave potential, 3.05 A/mgPGM of mass activity, and 8.58 mA/cmPt2 of specific activity. This systemic strategy not only proposes a novel and facile approach for the synthesis of ternary alloy catalysts but also reveals the intricacies of the catalytic activity, allowing the application of ternary alloy electrocatalysts.