Strategies to Enhance CO(2) Electrochemical Reduction from Reactive Carbon Solutions

CO(2) electrochemical reduction (CO(2) ER) from (bi)carbonate feed presents an opportunity to efficiently couple this process to alkaline-based carbon capture systems. Likewise, while this method of reducing CO(2) currently lags behind CO(2) gas-fed electrolysers in certain performance metrics, it offers a significant improvement in CO(2) utilization which makes the method worth exploring. This paper presents two simple modifications to a bicarbonate-fed CO(2) ER system that enhance the selectivity towards CO. Specifically, a modified hydrophilic cathode with Ag catalyst loaded through electrodeposition and the addition of dodecyltrimethylammonium bromide (DTAB), a low-cost surfactant, to the catholyte enabled the system to achieve a FE(CO) of 85% and 73% at 100 and 200 mA·cm(−2), respectively. The modifications were tested in 4 h long experiments where DTAB helped maintain FE(CO) stable even when the pH of the catholyte became more alkaline, and it improved the CO(2) utilization compared to a system without DTAB.