Precisely constructing subsurface electron pump stabilizes Pt catalysts against oxygen-induced degradation in fuel cells

Conventional methods to mitigate surface active sites dissolution in Pt-based fuel cell catalysts (Pt/C) often lead to loss of electrochemically active surface areas or dealloying. Here, we report a strategy via atomic layer deposition to precisely introduce a nonmetallic single-atom electron pump into unstable Pt subsurface, regulating oxygen adsorption and inhibiting inward diffusion. Boron single atoms significantly enhance Pt dissolution resistance, resulting in an initial peak power density of 1.76 W cm −2 for Pt/C, only 16.8% mass activity loss after 30,000 cycles test (projected lifetime >30,000 h, exceeding DOE 2025 targets), and ultrahigh stability over 200 h rated operation with negligible current declines. In situ characterizations and DFT calculations reveal that subsurface-doped-boron-induced asymmetric strain weakens oxygen species adsorption, blocks oxygen penetration, and continually pumps electrons to surface unsaturated Pt sites to suppress oxidation dissolution. This work provides a generalizable and scalable approach for stabilizing Pt-based catalysts through atomic-level subsurface engineering.