Photocatalytic and electrocatalytic reduction of CO2 to methanol by the homogeneous pyridine-based systems

•The visible light driven pyridine catalytic reduction of CO2 to methanol in aid of ruthenium phenanthroline complex.•Pyridine/ruthenium phenanthroline exhibits high product selectivity and efficient productivity with 60 μmol/L of methanol.•The process can be used in remote fields and produces a much higher selectivity and efficient value product.

The visible light driven pyridine catalytic reduction of CO2 was performed in aid of ruthenium phenanthroline complex photosensitizer. The light absorbance and utilization of the catalytic system was identified using UV–vis absorption and emission spectroscopic techniques. Under the dark conditions, electrochemical properties of the catalytic system were evaluated by compared the redox properties under N2 and CO2 pressure, respectively. Then, the photocatalytic CO2 reduction with this catalytic system was studied under the visible light (λ > 420 nm) irradiation. The gaseous and liquid products of the CO2 reduction were analyzed using gas chromatography and liquid chromatography. Methanol was the main product and there were no other products determined in the present system. The photocatalytic system showed a high product selectivity and efficient productivity with 60 μmol/L of methanol as solo product under the optimized conditions.

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