Designing a Zn–Ag Catalyst Matrix and Electrolyzer System for CO2 Conversion to CO and Beyond

CO2 emissions can be transformed into high‐added‐value commodities through CO2 electrocatalysis; however, efficient low‐cost electrocatalysts are needed for global scale‐up. Inspired by other emerging technologies, the authors report the development of a gas diffusion electrode containing highly dispersed Ag sites in a low‐cost Zn matrix. This catalyst shows unprecedented Ag mass activity for CO production: −614 mA cm−2 at 0.17 mg of Ag. Subsequent electrolyte engineering demonstrates that halide anions can further improve stability and activity of the Zn–Ag catalyst, outperforming pure Ag and Au. Membrane electrode assemblies are constructed and coupled to a microbial process that converts the CO to acetate and ethanol. Combined, these concepts present pathways to design catalysts and systems for CO2 conversion toward sought‐after products. Catalysts, electrodes, and membrane electrode assemblies (MEAs) are developed for the electrocatalytic conversion of CO2‐to‐CO and beyond. The system consists of highly porous Ag dispersed in a Zn matrix, which leads to high CO2 utilization as described by multiphysics modeling. Coupling to microbiology allows for further upgrading to multicarbon products.