Highly Efficient Bipolar Membrane CO<sub>2</sub> Electrolysis
Mrinmay Mandal
Abstract
Abstract CO 2 reduction reaction (CO 2 RR) is a promising way to convert CO 2 into value‐added products. Membrane‐based gas‐phase CO 2 RR offers several advantages like high selectivity and energy efficiency. However, high product crossover and poor CO 2 utilization in anion exchange membranes (AEMs) prevents the utilization of AEMs for CO 2 RR. The acidic environment of the cation exchange membrane can negatively influence the CO 2 reduction reaction (CO 2 RR) activity by favoring the competing hydrogen evolution reaction (HER). Hence, it is necessary to manipulate the local pH environment of the electrodes to yield maximum productivity. Bipolar membranes (BPMs) with a cation exchange layer (CEL) and an anion exchange layer (AEL) help in maintaining different local pH environments at each electrode. Now, a bipolar membrane fabrication with a weak‐acid cation exchange layer removes the possibility of competing HER without affecting CO 2 RR.