Maintaining local alkalinity of CO-electroreduction full cell by silica-confined electrocatalysts in membrane electrode assembly

CO electroreduction in alkaline membrane electrode assembly represents an effective approach to achieve carbon neutrality. However, its performance is currently limited by the insufficient modulation of local alkalinity at a full cell level. In this work, we reveal that confining the in-situ generated OH− at cathode and enriching the bulk OH− to anode are the key factors for an efficient CO-electroreduction full cell. We thereby propose a silica-confined strategy for electrocatalyst design to maintain high local alkalinity at both cathode and anode by the strong Lewis acid-base interaction between highly electrophilic Si atom and OH−. The developed Cu/SiO2 cathode and Co/SiO2 anode successfully promote cathodic multi-carbon formation and anodic oxygen evolution, thereby improving the full cell energy efficiency. Even under high-rate electrolysis at 900 mA cm −2, the selectivity and energy efficiency of multi-carbon products remains above 80% and 30%. This achievement highlights the significance of modulating the dynamic OH⁻ transport at full cell in enhancing CO electroreduction performance.