Toward a Stackable CO₂-to-CO Electrolyzer Cell Design─Impact of Media Flow Optimization

Aqueous CO2-to-CO electrolysis is a promising technology for closing the carbon cycle and defossilizing industrial processes. Considering technological readiness, consensus has been achieved about using silver as stable selective electrocatalyst reduction reaction in aqueous electrolyte. On other hand, challenges such media flow management, component stability, force distribution are still associated with improving process performance developing stackable cell concept to meet industrially relevant levels. We therefore report on stack continuous flowcells operated gas diffusion electrodes (GDEs). To enhance conversion efficiency, dedicated chambers were developed two In chamber, which touches GDE from far side of anode, feed over controlled by introducing various path architectures modular flowcell. addition, an ionically conductive spacer was implemented catholyte adjacent opposite GDE. The effect these modifications voltage, selectivity, overall investigated at 100 mA/cm2 varying CO2 concentration. Noteworthy, optimized generated increase Faraday efficiency CO under reduced supply. Furthermore, implementation enhanced stability suppressing gas-bubble-induced noise voltage measurements. By functioning support structures GDE, combined provided mechanical integrity allowed ionic electric contact full active area, required both stacking upscaling cell. corresponding demonstrated two-cell short-stack.