Single-Atom Mediated d-Band Engineering of Platinum Nanocatalysts for High-Efficiency Acidic Hydrogen Evolution

The rational construction of single-atom-mediated Pt catalysts with optimized electronic structures and robust stability remains a grand challenge for hydrogen evolution reaction (HER). Herein, spatial confinement coupled with a d-band engineering strategy is pioneered to fabricate cobalt single-atom coordinated Pt nanocatalysts (Pt@Co-SAs/NC), achieving exceptional HER activity with ultralow Pt loading (0.94 wt%). The Pt@Co-SAs/NC exhibits an overpotential of 15 mV at 10 mA cm^-2 (η₁₀) and 21.8-fold enhanced mass activity at 20 mV versus commercial Pt/C, surpassing most reported Pt-based systems. Synchrotron X-ray absorption spectroscopy and theoretical studies reveal that the atomically dispersed CoN₄ sites adjacent to Pt NPs serve as electronic modulators, inducing a 0.36 eV downshift of the Pt d-band center through interfacial charge redistribution. This electronic engineering weakens hydrogen adsorption strength (ΔG_H* = -0.17 eV) while accelerating H₂ desorption kinetics. Furthermore, the CoN₄-anchored carbon matrix suppresses nanoparticle aggregation and ensures exceptional durability through strong metal-support interactions, maintaining 94.2% activity after 130 h operation. This work establishes an atomic-level electronic modulation paradigm for designing highly efficient, cost-effective, and durable electrocatalysts.