Zinc-phosphorus nanodomains with dynamic coordination for electrochemical CO2 reduction

Single-atom catalysts (SACs) are favored owing to their well-defined motifs and notable CO selectivity in electrochemical CO2 reduction. However, the dynamic coordination evolution under working conditions and the structure-activity relationships remain highly puzzling. Herein, we suggest that flexible Zn–P3 nanodomains with weak-bond interactions may exhibit a potential-dependent structural modulation under working conditions compared to Zn–N4 configurations. A possible metastable state with reduced Zn–Px-like coordination may be formed from the Zn–P3 structure under CO2 reduction working conditions. Based on in situ spectroscopy analysis, deuterium isotope kinetic analysis, and theoretical calculations, the low-coordination Zn and the possibly perturbed P sites may serve as efficient active sites for the first step of sequential proton–electron transfer in the CO2 electroreduction. The collaborative assignments within this dynamic catalytic nanodomain, rather than at individual metal site, may contribute to the improved the intrinsic activity, which delivers a high turnover frequency (47,690 h−1) and a CO production rate (213 mL h−1 cm−2) at 500 mA cm−2 for 100 h. Our work elucidates the dynamic coordination-governed mechanisms of SACs and underscores the necessity of probing their structural basis under operating conditions. The dynamic coordination changes of single-atom catalysts during CO2 electroreduction are unclear. Here, the authors report Zn–P3 nanodomains undergo potential-dependent structural modulation, revealing coordination-governed electroreduction mechanisms.