(651g) Recovering Carbon Losses in CO2 Electrolysis Using a Solid Electrolyte Reactor

The practical implementation of electrochemical CO₂ reduction technology is greatly challenged by significant CO₂ crossover to the anode side, where the crossed-over CO₂ is mixed with the O_2, via interfacial carbonate formation in traditional CO₂ electrolyzers. Here we report a porous solid electrolyte reactor strategy to efficiently recover these carbon losses. By creating a permeable and ion-conducting sulfonated polymer electrolyte layer between cathode and anode as a buffer layer, the crossover carbonate can combine with protons generated from anode to re-form CO₂ gas for reuse without mixing with anode O₂. Using silver nanowire catalyst for CO₂ reduction to CO, we demonstrated up to 90% recovery of the crossover CO₂ in an ultrahigh gas purity form (> 99%), while delivering over 90% CO Faradaic efficiency under 200 mA/cm² current. A high continuous CO₂ conversion efficiency of over 90% was achieved by recycling the recovered CO₂ to the CO₂ input stream.