Molecular Catalyst with Near 100% Selectivity for CO2 Reduction in Acidic Electrolytes

The electrocatalytic carbon dioxide reduction reaction (CO2RR) in an acidic medium is conducive to the efficient utilization of CO2 by preventing the formation of carbonate/bicarbonate. However, acidic media are more favorable for the hydrogen evolution reaction (HER), resulting in unsatisfactory CO2RR selectivities. It is demonstrated that the molecularly dispersed electrocatalyst of β‐tetra methoxy‐substituted nickel phthalocyanine on carbon nanotubes (NiPc‐OMe MDE) can efficiently catalyze CO2RR in acidic media (pH 2 to 0.47) with Faradaic efficiencies of CO >98% over a wide range of current densities from −50 to −400 mA cm−2. It is found that the superior selectivity performance can be attributed to the presence of potassium ions, the high preference of CO2RR over HER on the active site, and few side reaction sites. The study illuminates the potential of molecular electrocatalysts for selective and rapid reduction of CO2 in acid media. The molecularly dispersed electrocatalyst of β‐tetra methoxy‐substituted nickel phthalocyanine on carbon nanotubes can electrocatalyze the CO2 reduction in acid with near 100% CO selectivity over a wide range of current densities. The presence of potassium ions, the preference for the CO2 reduction, and few side reaction sites are found to be the keys for such high selectivities.