Spin-polarized co enhances interactions between PtCoCu alloys and composite carbon substrates for efficient oxygen...

To address the low site density caused by insufficient mass transfer structure of metal‑nitrogen‑carbon (M-N-C) materials and the high cost of Pt-based oxygen reduction reaction (ORR) catalysts, a dual-structure engineering strategy is proposed to establish synergistic interactions between ultrafine Pt-Co-Cu alloys and hierarchical porous composite carbon supports. Specifically, zeolitic imidazolate framework-8 (ZIF-8)-derived Cu-NC is integrated with porous carbon to form Cu-NC@C substrates, which provide abundant exposed surface sites and hierarchical pores for enhanced anchoring of the Pt-Co-Cu ternary alloys. The synergistic electronic effect of the Co/Cu bimetallic system optimizes the d-band center of Pt, precisely tuning oxygen intermediates adsorption energy and boosting ORR performance. Experimental results demonstrate that the PtCoCu/Cu-NC@C catalyst exhibits exceptional ORR activity, with a mass activity of 0.5 ± 0.1 A mg_Pt^-1 at 0.9 V, a half-wave potential of 0.93 ± 0.01 V, negligible performance decay after 20,000 cycles, and a peak power density of 160.5 mW cm^-2 in a zinc-air battery. Integrated experimental-theoretical analyses confirm that the enhanced ORR performance originates from third-metal-induced charge transfer process and Co's spin-polarization effect, which synergistically strengthen metal-support interactions between the carbon substrate and Pt-Co-Cu alloys. This study presents a novel strategy for designing high-performance, low-Pt ORR catalysts through integrated electronic structure optimization with multiscale mass transfer transport engineering.