A Separations Perspective on Low-Temperature CO2 Electrolysis

Electrochemical reduction of CO2 to valuable chemicals is a fast-developing power-to-X concept for decarbonizing hard-to-abate sectors. While intensive research in the past two decades has enabled production of several value-added chemicals at high current densities and selectivities with low cell voltages, separations required to deliver these products at market purity have received far less attention. In this perspective, we present a list of parameters that capture the separations problem, characterize the drivers of separations difficulty in CO2R systems, and outline best practices for conducting techno-economic analysis, integrating upstream and downstream separations, such that separations are codesigned with the reactor rather than treated as an afterthought.