Anodic Generation of Lewis Acid for the Electrochemical Synthesis of Methyl Formate from CO2

Electro-oxidation of neutral substrates to produce cationic species, such as protons or metal cations to serve as Bronsted acids or Lewis acids, can potentially be coupled with the CO 2 reduction reaction at the cathode. In particular, coupling the electrochemical CO 2 reduction reaction with the anodic generation of a Lewis acid can be a new approach to synthesizing new products from CO 2 while avoiding a high proton environment. In this study, we explored the coupling of the anodic Lewis acid generation by the dissolution of a titanium anode and the cathodic production of formate from CO 2 in a methanol electrolyte. As a result, we observed methyl formate as a CO 2 conversion product with the highest faradaic efficiency of 69% under ambient conditions. Interestingly, methyl formate was observed only when NaBF 4 was used in an undivided electrochemical cell, whereas only formic acid/for…