Spherical Bi2O3/ATO catalyst with N2 pre-reduction electrocatalytic reduction of CO2 to formic acid

Bi 2 O 3 catalyst with Bi-O bond crystal structure has more active sites, which shows better CO 2 catalytic performance than pure Bi catalysts in many catalytic reactions. How to strengthen the Bi-O bond in Bi 2 O 3 to obtain higher selectivity and catalytic activity is a problem worthy of consideration. Here, we develop a N 2 pre-reduced spherical Bi 2 O 3 /ATO catalyst that has a high formate Faradaic efficiency of 92.7%, which is superior to the existing tin oxide catalyst. Detailed electrocatalytic analysis shows that N 2 pre-reduction and spherical structure are helpful for Sn to stabilize the oxidation state of Bi, thus retaining part of the Bi-O structure. The existence of the Bi-O structure can reduce the energy barrier of the CO 2 production *OCHO reaction and promote the reaction rate of the CO 2 -*OCHO-HCOOH path, thus promoting the formation of formate.