The Ce → Pt electron pump across N-rGO for superior hydrogen evolution

Conventional strategies for enhancing platinum’s hydrogen evolution reaction (HER) activity, like alloying or heteroatom-doping, usually suffer from component leaching. We presented a paradigm shift from modifying Pt to remotely engineering its electronic environment. By co-anchoring isolated Ce single atoms, Pt single atoms, and Pt nanoclusters on an N-doped reduced graphene oxide (Ce₁-Pt₁Pt_n/N-rGO) matrix, we constructed an atomic-scale “electron pump”. The architecture enables the unidirectional and spontaneous flow of electrons from the Ce sites, through the N-rGO conduit, into Pt active centers as validated experimentally and theoretically. This remote charge donation optimally tailors the Pt electronic structure, down-shifting its d-band center and optimizing the hydrogen adsorption. The resulting catalyst achieves an ultralow overpotential of 20 mV at 10 mA·cm⁻² and a superior Pt mass activity of 7.0 A·mg_Pt⁻¹ at −200 mV, outperforming commercial Pt/C and the Pt₁Pt_n/N-rGO benchmark. Furthermore, it exhibits exceptional stability, retaining an activity of more than 92% after 200 h. This work establishes a novel “remote electron modulator” catalysts, providing a generic pathway for optimizing the performance of noble metals beyond traditional alloy or strain effects.