Electrochemically modulated complexation process for gas removal and concentration

An electrochemically modulated complexation process was designed to extract and concentrate a gas‐phase solute. The process was based on flowthrough electrolysis cells that electrochemically modulate a liquid‐phase mass‐transfer agent between high and low solute affinity forms. The liquid phase in the high‐affinity form contacts a feed gas phase for the extraction and contacts the receiving gas phase in the low‐affinity form. The chemical system used to demonstrate the general process was a Cu(II)/Cu(I) redox couple in an acidic chloride electrolyte to both concentrate carbon monoxide against a pressure gradient and selectively separate it from a mixture with nitrogen. Experimental results and modeling of this process are reported. The kinetics of the electrolysis reactions in the flow cells are discussed within the context of rotating ring disk voltammetry experiments.