CO₂Electrolysis to CO and O₂at High Selectivity, Stability and Efficiency Using Sustainion Membranes

Carbon dioxide (CO 2 ) electrolysis provides a pathway to close the anthropogenic carbon cycle and store renewable energy, but the stability, selectivity, efficiency and rate of such process needs to be improved. In this paper, we explore the use of Sustainion imidazolium-functionalized membranes and ionomers to improve the performance of that process. Potentiometric runs at a fixed current of 200 mA/cm 2 using Sustainion membranes and ionomers showed that one can maintain 98% selectivity at about 3V applied potential for five months, with a voltage increase of only 3 μV/hour. Other runs showed stable performance at 400 and 600 mA/cm². These results pave the way for commercialization of CO 2 electrolysis, providing a viable pathway to recycle CO 2 back to fuels.