Copper phenanthroline for selective electrochemical CO₂ reduction on carbon paper

We report a series of structurally relevant copper phenanthroline complexes as pre-catalysts for highly selective electrocatalytic reduction of CO₂ to C₂ products using inexpensive carbon paper electrodes. The Cu complexes with non-substituted phenanthroline promote the production of ethylene with a high faradaic efficiency of 71.2%, while the one with pyridinium-functionalized ligands is more selective for ethanol. The C₂ selectivity can be effectively tuned by increasing the number of coordinated phenanthrolines and remains high at a wide range of potentials.