CO 2 Electroreduction from Carbonate Electrolyte

The process of CO 2 valorization—from capture of CO 2 to its electrochemical upgrade—requires significant inputs in each of the capture, upgrade, and separation steps. Here we report an electrolyzer that upgrades carbonate electrolyte from CO 2 capture solution to syngas, achieving 100% carbon utilization across the system. A bipolar membrane is used to produce proton in situ to facilitate CO 2 release at the membrane:catalyst interface from the carbonate solution. Using a Ag catalyst, we generate syngas at a 3:1 H 2:CO ratio, and the product is not diluted by CO 2 at the gas outlet; we generate this pure syngas product stream at a current density of 150 mA/cm 2 and an energy efficiency of 35%. The carbonate-to-syngas system is stable under a continuous 145 h of catalytic operation. The work demonstrates the benefits of coupling CO 2 electrolysis with a CO 2 capture electrolyte on the pa…