Selective reduction of CO 2 to formate through bicarbonate reduction on metal electrodes: new insights gained from SG/TC mode of SECM

We discovered using SECM of the electro-reduction of CO 2 on a Au substrate in CO 2 -saturated KHCO 3 solutions that (i) formate comes solely from the direct reduction of bicarbonate; and (ii) CO forms only from CO 2 reduction (under low pH conditions) and at higher applied potentials. The results point to the possibility of the selective reduction of CO 2 to the formate product.