Sustainable at both ends: electrochemical CO utilization paired with electrochemical treatment of nitrogenous waste

We discuss the environmental and energetic benefits of coupling nitrogenous waste treatment with the electrochemical conversion of CO 2 to value-added products via direct reduction or electrocarboxylation. In particular, we demonstrate that co-electrolysis of urea or ammonia with CO 2 requires significantly lower cell voltages than CO 2 electrolyzers relying on the oxygen evolution reaction as an anodic process. Optimizing CO2 electrolyzer cell voltage requirement: aqueous and organic reductive electrocatalysis paired with electrooxidation of urea and ammonia.