Bismuth Iron Oxide Catalysts for Efficient CO 2 Electroreduction to Formate.

Renewable energy-driven electrocatalytic CO 2 reduction reaction (CO 2 RR) over bismuth-based catalysts shows great promise for converting CO 2 into formic acid and formate while closing the carbon cycle. Herein, we report a high-performance BiFeO 3 /Bi 25 FeO 40 precatalyst, which delivers a formate partial current density of 359.8 mA cm -2 and a formate formation rate of 6.71 mmol h -1 cm -2 in a flow cell at -0.75 V versus reversible hydrogen electrode (vs RHE). Furthermore, it shows stable formate production for 88 h at -0.64 V vs RHE with a total current density of 160 mA cm -2 . The impressive electrocatalytic performance toward CO 2 RR to formate is likely ascribed to the synergistic effect of single Bi atoms and bimetallic BiFe nanoparticles present in close proximity after in situ electrochemical reconstruction of the BiFeO 3 /Bi 25 FeO 40 precatalyst. This work presents new insights into the development of highly efficient Bi-based catalysts for the CO 2 RR.