Efficient electron transfer between the electrode surface and an immobilized metal complex is necessary to accelerate a catalytic reaction, efficient electron transfer can introduce a boost in catalytic activity. Non-covalent immobilization of a molecular electrocatalyst was also applied in an oxygen reduction reaction and oxygen evolution reaction with a pyrene-modified cobalt complex (Figure ). High activity and durability were observed when a fluoro-substituted cobalt compound was immobilized on multi-walled carbon nanotubes. A four-electron reduction of oxygen to water in an acidic aqueous solution was achieved with an onset potential of 0.75 V vs. a normal hydrogen electrode (NHE). In comparison, water oxidation in a neutral aqueous solution was performed with an onset potential of 1.15 V vs. NHE. Compared to the molecular cobalt complex, an enhanced catalytic performance was observed, likely due to the strong π-π interactions between the catalyst and the electrode enabling efficient electron transfer for both reactions.