Electronic Structure Engineering of Pt–Ni Alloy NPs by Coupling of Gold Single Atoms on N-Doped Carbon for Highly Efficient Oxygen Reduction Reaction and Hydrogen Evolution Reaction

Improving the catalytic activity and durability of platinum-based alloy catalysts remains a formidable challenge in the context of renewable energy electrolysis applications. Herein, a facile and rapid photochemical deposition strategy for the synthesis of gold single atoms (Au SAs) anchored on N-doped carbon is presented. These Au SAs serve as a charge redistribution support for Pt–Ni alloy nanoparticles (PtNi_NPs/Au_SA-NDC), creating an extended electron-donating interface with Pt–Ni alloy sites. Consequently, the PtNi_NPs/Au_SA-NDC hybrid catalyst manifests exceptional catalytic performance and durability in both the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) under acidic conditions. Specifically, in ORR, it exhibits a half-wave potential (0.92 V vs RHE), with a mass activity 20.4 times superior to Pt/C at 0.9 V. In HER, PtNi_NPs/Au_SA-NDC demonstrates a notably reduced overpotential of 19.1 mV vs RHE at 10 mA cm⁻² and a mass activity 38 times higher than Pt/C (at 0.25 mV). Furthermore, this hybrid catalyst displays outstanding durability, with only an 8.0 mV decay observed for ORR and a 6.9 mV decay for HER after 10 000 cycles. Theoretical calculations provide insight into the mechanism, demonstrating that isolated Au sites effectively modulate the electronic structure of Pt–Ni alloy sites, facilitating intermediate adsorption and enhancing reaction kinetics.