Utilizing nitrogen vacancy to tune oxygen adsorption of co atoms and boost oxygen reduction reaction kinetics in Zn-air batteries

Regulating the coordination structure of single-atom catalysts (SACs) is an effective strategy to enhance oxygen reduction reaction (ORR) activity and zinc-air battery (ZAB) performance. However, asymmetric coordination configurations often suffer from poor structural stability during long-term operation, limiting their practical applicability. To address this challenge, this study introduces a Co single-atom catalyst (Co-SAs/N V PC) featuring a shell-structured architecture with strategically positioned pyridinic-N vacancies adjacent to stable Co N 4 sites. The introduction of vacancies shifts the d-band center of Co closer to the Fermi level, weakening the binding strength of *OH and thereby enhancing both the activity and selectivity of the ORR, as confirmed by in-situ surface-enhanced Raman spectroscopy (SERS) and Fourier-transform infrared (FTIR) analyses. Temperature- and potential-dependent scanning electrochemical microscopy (SECM) further offers deeper insights into the dynamic catalytic behavior under operational conditions. When integrated into ZABs, Co-SAs/N V PC delivers a peak power density of 203.4 mW cm −2 , a specific capacity of 775 mAh g −1 , and sustains 58% capacity retention after 1000 cycles at 10 mA cm −2 . This work establishes a design paradigm for SACs in sustainable energy systems by bridging atomic-scale electronic tailoring with macroscopic energy conversion efficiency.