Dual Pt-Ni atoms dispersed on N-doped carbon nanostructure with novel (NiPt)-N₄C₂ configurations for synergistic electrocatalytic hydrogen evolution reaction

Single-atom catalysts with high atomic utilization efficiency, well-defined active centers, and catalytic sites with low atomic coordination numbers are promising to boost electrocatalytic performance. Dual-atom catalysts (DACs) with neighboring heteroatoms are expected to exert the synergistic effect of the two atoms, further improving the activity. Herein, we report a PtNi-NC catalyst consisting of PtNi dual atoms anchored on a nitrogen-doped carbon substrate synthesized through atomic layer deposition. X-ray absorption spectroscopy confirms the existence of the PtNi dual atoms. The as-prepared PtNi-NC catalyst exhibits extraordinary catalytic activity, with an overpotential of 30 mV for hydrogen evolution reaction (HER) in acidic media at a current density of 10 mA cm⁻², which is comparable to that of commercial 20 wt% Pt/C. Notably, PtNi-NC possesses a much higher mass activity, about 21 times, than 20 wt% Pt/C. Density functional theory calculations reveal that PtNi dual atoms generate a synergistic effect by modulating the local electronic structure and optimizing the charge distribution, contributing to optimized adsorption properties and enhanced electrocatalytic performance. This work provides a new avenue for the fabrication of DACs, revealing their potential applications in electrocatalytic HER and beyond. [Figure not available: see fulltext.].