AbstractWe have studied two structurally related, water‐insoluble ruthenium complexes [RuII(tpy*)(phenCO2)](PF6) (1) (tpy*=5,4′,5′′‐tri‐tert‐butyl‐2,2′;6′,2′′‐terpyridine; phenCO2H=1,10‐phenanthroline‐2‐carboxylic acid) and [RuII(tpy)(dmphen)(Cl)](PF6) (2) (tpy=2,2′;6′,2′′‐terpyridine; dmphen=2,9‐dimethyl‐1,10‐phenanthroline, also known as neocuproine) and their electrocatalytic activity for CO2 reduction in acetonitrile and after immobilization on the reduced graphene oxide (rGO) in water (pH 7.2). Under homogeneous conditions (in CO2 saturated acetonitrile solution), characteristic major CO2 reduction waves indicate ∼280 mV lower overpotential upon changing the catalyst from 1 to 2. The higher CO2 electroreduction performance of 2 is also reflected on the heterogeneous rGO surfaces.