Bismuth-Based Electrocatalysts for Identical Value-Added Formic Acid Through Coupling CO 2 Reduction and Methanol Oxidation.

It is an effective way to reduce atmospheric CO 2 via electrochemical CO 2 reduction reaction (CO 2 RR), while the slow oxygen evolution reaction (OER) occurs at the anode with huge energy consumption. Herein, methanol oxidation reaction (MOR) is used to replace OER, coupling CO 2 RR to achieve co-production of formate. Through enhancing OCHO* adsorption by oxygen vacancies engineering and synergistic effect by heteroatom doping, Bi/Bi 2 O 3 and Ni─Bi(OH) 3 are synthesized for efficient production of formate via simultaneous CO 2 RR and methanol oxidation reaction (MOR), achieving that the coupling of CO 2 RR//MOR only required 7.26 kWh g formate -1 power input, much lower than that of CO 2 RR//OER (13.67 kWh g formate -1 ). Bi/Bi 2 O 3 exhibits excellent electrocatalytic CO 2 RR performance, achieving FE formate >80% in a wide potential range from -0.7 to -1.2 V (vs RHE). For MOR, Ni─Bi(OH) 3 exhibits efficient MOR catalytic performance with the FE formate >98% in the potential range of 1.35-1.6 V (vs RHE). Not only demonstrates the two-electrode systems exceptional stability, working continuously for over 250 h under a cell voltage of 3.0 V, but the cathode and anode can maintain a FE of over 80%. DFT calculation results reveal that the oxygen vacancies of Bi/Bi 2 O 3 enhance the adsorption of OCHO* intermediate, and Ni─Bi(OH) 3 reduce the energy barrier for the rate determining step, leading to high catalytic activity.