Cascade Electrocatalytic Conversion of CO to C Products at Elevated Pressures.

Recent progress in the electrochemical reduction of CO (CORR) has led to notable breakthroughs in generating C compounds such as ethylene and ethanol. Nevertheless, the direct formation of C products encounters significant limitations due to the C-C coupling reaction, posing a considerable challenge to improving their faradaic efficiency. Here, a design for an elevated pressure cascade catalytic reactor to convert CO to C products in a two-step electrochemical process is presented. At 25 bar pressure, by regulating the potential of the cascade system and the electrolyte flow rate, a 40% selectivity for 2-propanol on a copper electrode placed upstream of a silver electrode that converts CO to CO is reported. In cascade mode (with both silver and copper electrodes active), the C:C oxygenate ratio significantly increases to 7 compared to the noncascade mode (copper only) with a modest ratio of about 0.6. Therefore, our elevated pressure cascade electrolysis approach demonstrates a notable step forward in CO electroreduction to oxygenated C products.