Design of gas diffusion electrode electrolyzer for CO2 reduction to CO with Cl2 and Na2CO3 produced as by-products

A novel gas diffusion electrode (GDE) electrolyzer has been constructed to convert CO 2 into CO, with chlorine (Cl 2 ) and sodium carbonate (Na 2 CO 3 ) produced as the by-products. Using this method, the product value yielded from CO 2 electrolysis can be increased substantially. In contrast to the conventional GDE electrolyzer, we use a cation-exchange membrane as the diaphragm to separate the cathode from the anode compartment, and use NaCl aqueous solution as the anolyte. During the electrolysis process, CO 2 is reduced to CO on the cathode, with CO 3 2− generated accompanied with CO formation. On the anode, Cl − is oxidized to Cl 2 . Na + in the anode chamber transfers through the cation-exchange membrane, and migrates into the catholyte. Thus, Na 2 CO 3 can be obtained owing to the co-existing of Na + and CO 3 2− in the catholyte. Using this method, CO 3 2− penetrating through the anion-membrane can be avoided. This problem has been considered as the crucial obstacle that impedes the practical utilization of the conventional GDE electrolyzer. Our designed GDE electrolyzer has a promising application perspective in the phosgene chemical industry.