摘要
The sluggish kinetics of the oxygen reduction reaction (ORR) and the high cost of Pt-based catalysts remain major barriers for alkaline fuel cell (AFC) technologies. Here we report a Cu-decorated CoO@Pd catalyst in which atomic-to-subnanometer CuOx species reconstruct the Pd-Co-Cu heterointerface and enable a cooperative multi-site ORR pathway. Structural and spectroscopic analyses reveal that low Cu loading produces atomically dispersed CuOx motifs that enrich oxygen vacancies (OV)s, preserve metallic Pd, and stabilize oxygen-deficient Co3 + centers. Operando PFY-XANES/EXAFS further uncovers a synergistic mechanism in which OVs around Cu serve as rapid O2 activation sites, Pd mediates lateral *Oads spillover, and OVs around Co act as the primary *Oads reduction centers. This division of labor maximizes four-electron ORR kinetics, yielding a on-set potential of 0.935 V and a mass activity (MA) of similar to 1.6 & times; 104 mA mgCu - 1 without decay for 50k potential cycles, surpassing commercial Pt/C by over two orders of magnitude. When integrated into AFCs, the optimized catalyst (CPCu-1) delivers a peak power density of similar to 430 mW cm- 2, approximately 60% higher than Pt/C, and exhibits a characteristic three-stage durability governed by dynamic CuOx-CoOx interface reconstruction. These findings establish atomic CuOx interface engineering strategy for designing high-performance, noble-metal-efficient ORR catalysts.