Heteroatomic Platinum–Cobalt Synergetic Active Centers with Charge Polarization Enable Superior Hydrogen Evolution Performance in both Acid and Base Media

Rational design of heterosynergistic active moieties can significantly improve the intrinsic activity and mechanistic understanding for electrolytic hydrogen evolution reaction (HER), especially crucial to precious platinum group catalysts. Here, we report an alloying Pt with Co atoms to achieve atomic-scale catalytic synergy via spontaneous electronic alteration, resulting in an excellent PtCo nanoalloy catalyst for hydrogen evolution reaction (HER) suitable in both acid and base media. The resultant porous carbon-supported PtCo nanoalloy catalyst enables superior HER performance with high Pt-mass activity, surpassing commercial Pt/C and most state-of-the-art catalysts reported. Combined experimental and theoretical studies reveal that the charge redistribution on adjacent Pt and Co atom sites in alloys optimizes their d-band center positions and creates dual-atomic synergistic active units for intermediate H* and OH* transfers, responsible for highly intrinsic HER activity, especially with water-dissociation activation in basic condition. This work not only develops a low Pt-content HER catalyst but also provides deep insights into synergy modulation for rational design of advanced catalysts.