Design of a High Throughput 25‐Well Parallel Electrolyzer for the Accelerated Discovery of CO₂ Reduction Catalysts via a Combinatorial Approach

A combinatorial approach is described for screening homogeneous CO 2 reduction electrocatalysts by means of a high‐throughput 25‐well parallel electrolyzer. Active catalysts were then screened by three methods: (1) the presence of CO gas in the electrolyzer head space; (2) a pH change for the individual solutions before and after bulk electrolysis due to proton consumption during CO 2 reduction; and (3) other physical attributes. Based on these screening methods, two solutions out of the 25 were selected for further study. One out of two selected solutions, nickel cyclam, a well‐known CO 2 reduction electrocatalyst, was correctly identified to be the most active.