Designing Bi‐In₂O₃ Nanoflower Catalysts for Enhanced Performance of Electrochemical CO₂ Reduction to Formate

Electrochemical CO 2 reduction (ECO 2 RR) is capable of converting CO 2 into a wide range of value‐added products under relatively mild conditions. Electrocatalyst with high selectivity and activity is crucial for high efficient ECO 2 RR. Herein, Bi‐In 2 O 3 nanoflower catalysts with different metal ratios synthesized by wet chemical method are used for ECO 2 RR to produce formate. The results indicate that the hydrogen evolution activity of the Bi‐In 2 O 3 catalysts during ECO 2 RR is suppressed at a low level and the activity and selectivity of formate production is related to the ratio of Bi to In content in the catalysts. The optimized Bi‐In 2 O 3 catalyst with the ratio of Bi 6 In 94 can achieve a high formate Faradaic efficiency (FE formate ) over 80 % under a wide potential range from −0.7 V to −1.2 V vs. RHE, with the maximum value of 88.1 % at −0.7 V vs. RHE. Meanwhile, the highest formate partial current density reaches 47.7 mA cm −2 at −1.2 V vs. RHE and the current density and Faradaic efficiency remain stable during the 10 h stability test. The enhanced formate formation on Bi‐In 2 O 3 NF can be attributed to the synergistic effect between Bi and In according to the characterizations of the Bi‐In 2 O 3 NF.