Tuning Electronic Effects in P-Block Metal-C₆₀ Catalysts for Highly Selective CO₂ Reduction to Formate

Electrochemical CO₂ reduction (CO₂R) to formate offers a promising pathway toward sustainable chemical production. Although P-block metals display excellent selectivity, a universal approach for electronically tuning their active sites to simultaneously enhance activity and selectivity has remained challenging. In this work, we employ C₆₀ nanosheets as electron-buffering supports to modulate interfacial charge, and hence to improve the performance of P-block metals in CO₂R. Compared with pure indium (Pure In) catalyst, the C₆₀ nanosheets supported In nanoclusters catalyst (In-C₆₀) featuring high oxidation state achieves formate-dominated products across wide current densities, with high faradaic efficiency for formate reaching about 93% at 900 mA cm^-2 under alkaline conditions and 97% at 700 mA cm^-2 in acid, as well as higher stability exceeding 210 h in alkaline media. Operando infrared spectroscopy reveals that In-C₆₀ promotes ^*OCHO formation, and fixed-potential density functional theory (DFT) calculations indicate that C₆₀ tunes the In─O antibonding states near the Fermi level, weakening intermediate binding and facilitating the following protonation to formate. The strategy extends to other P-block metals (Bi, Sn, Pb), with the same electronic-tuning effect. This work introduces a generalizable strategy for P-block metal electrocatalysts and a practical route toward efficient, sustainable chemical production.