CoPL exhibits a high product specificity with around ~80% CO selectivity even under and). The origin of the observed trends for TiO2|CotpyP and CP|CoPL at different CO2 concentrations remains unclear but may be attributed to their molecular structure, which provides intrinsic affinity towards CO2. In comparison with state-of-the-art molecular systems, such as the rhenium bipyridine electrocatalyst [Re(4,4-dimethyl-2,2-dipyridyl)(CO)3(triethanolamine)], which operates in a DMF/triethanolamine solvent mixture at variable CO2 concentrations (1, 10 and 100 %) under comparable flow conditions, CP|CoPL is three orders of magnitude more active (i.e., TOFCO = 0.5 h -1 after 24h at 10% CO2 vs 413 h -1 after 4h at 20% CO2, respectively). Without taking into account that CO2 is more soluble in organic solvents than in water (e.g. ~180 mM in DMF vs ~33 mM in water at 25 °C), these differences in performance could be tentatively associated to the catalytic mechanism of CO2 reduction, which enables cobalt porphyrins to achieve higher TOF than rhenium bipyridine electrocatalysts. KCl). Flow of CO2:N2 9 mL min -1 . CO2 concentration was varied stepwise between 0 vol%, 10 vol%, 20 vol%, 50 vol% and 100 vol% and balanced with N2.