A Nanocomposite of Bismuth Clusters and Bi₂O₂CO₃ Sheets for Highly Efficient Electrocatalytic Reduction of CO₂ to Formate

The renewable‐electricity‐driven CO 2 reduction to formic acid would contribute to establishing a carbon‐neutral society. The current catalyst suffers from limited activity and stability under high selectivity and the ambiguous nature of active sites. Herein, we report a powerful Bi 2 S 3 ‐derived catalyst that demonstrates a current density of 2.0 A cm −2 with a formate Faradaic efficiency of 93 % at −0.95 V versus the reversible hydrogen electrode. The energy conversion efficiency and single‐pass yield of formate reach 80 % and 67 %, respectively, and the durability reaches 100 h at an industrial‐relevant current density. Pure formic acid with a concentration of 3.5 mol L −1 has been produced continuously. Our operando spectroscopic and theoretical studies reveal the dynamic evolution of the catalyst into a nanocomposite composed of Bi 0 clusters and Bi 2 O 2 CO 3 nanosheets and the pivotal role of Bi 0 −Bi 2 O 2 CO 3 interface in CO 2 activation and conversion.