Morphology‐Controlled Bi 2 O 3 Nanoparticles as Catalysts for Selective Electrochemical Reduction of CO 2 to Formate

In this paper, Bi 2 O 3 electrocatalysts for the electroreduction of CO 2 to formate were synthesized with different morphologies, including nanoparticles and thin nanorods. Comparatively, Bi 2 O 3 nanoparticles have higher catalytic activity than Bi 2 O 3 thin nanorods. The Faradaic efficiency of formate formation at a moderate potential of −1.2 vs. RHE in aqueous solution could reach 91 %. In addition, a maximum current density for formate production of up to 22 mA cm −2 was achieved, which is almost 3 times higher than that of Bi 2 O 3 thin nanorods. In particular, the catalytic activity of the Bi 2 O 3 nanoparticle catalyst was almost stable over a 23‐hour period of electrolysis, exhibiting its application prospect in the electroreduction of CO 2 to formate.