Abstract
Incorporating nonmetallic elements into Pt-based alloys to form nonmetal-hybridized alloy catalysts represents a promising strategy for enhancing electrocatalytic activity and stability. Solvothermal synthesis has recently emerged as an efficient approach for doping nonmetals, e.g., nitrogen (N), into alloy interstitial sites. Judicious selection of nonmetal precursors governs the success of this synthesis. Herein, we employ melamine as a N-precursor to synthesize N-doped PtCuNiCo alloy via a solvothermal-annealing method, aiming to elucidate the mechanism of N-incorporation. Through experiments and molecular dynamics simulation, it is demonstrated that N atoms from melamine preferentially coordinate with cobalt and nickel ions in the solvothermal solution, driven by the strong affinity of cobalt and nickel ions for -NH 2 group, which in turn facilitates its dissociation from melamine. Thereafter, as metal ions are reduced and incorporated into the nascent alloy lattice, the coordinated N species are simultaneously embedded into the interstitial sites. Benefiting from this interstitial N-doping, the resulting PtCuNiCoN catalyst exhibits enhanced oxygen reduction reaction activity and durability.