Curvature-induced metal-support interaction regulates Co-N4 electronic structure for enhanced oxygen electrocatalysis

Single-atom catalysts (SACs) have advantages such as high atom utilization and well-defined active sites, and have been extensively studied in the field of oxygen electrocatalysis. However, current strategies for tuning the M-N 4 configurations predominantly focus on local coordination environments, which still makes it difficult to simultaneously optimize the balance of adsorption energies of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) intermediates. Herein, a Zn volatilization-induced pyrolysis strategy is developed to construct Co-N 4 sites coupled with Co nanoparticles on curved N-doped biomass-derived carbon (Co NPs + SA @NC). The intrinsic curvature and defect-rich structure induce lattice distortion and electronic polarization, significantly enhancing the metal-support interaction (MSI). This curvature-enhanced MSI triggers electronic reconstruction and symmetry breaking of Co-N 4 sites, narrowing the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap and facilitating electron transfer. Meanwhile, the influence of adjacent Co nanoparticles optimizes the electronic structure of Co-N 4 , improving the adsorption-desorption capacity of intermediates in the OER process. Therefore, the half-wave potential required to achieve ORR was 0.87 V, and the overpotential required to reach a current density of 10 mA/cm 2 is only 290 mV. A zinc-air battery (ZAB) based on Co NPs + SA @NC exhibited a high peak power density of 172 mW/cm 2 . This work highlights curvature-mediated MSI as an effective strategy for controlling single-atom configurations and advancing biomass-derived electrocatalysts.