CO2 reduction by C3N4-TiO2 Nafion photocatalytic membrane reactor as a promising environmental pathway to solar fuels

We investigated CO photocatalytic reduction coupling, for the first time in literature, the assets offered by the continuous operating mode using CN-TiO photo-catalyst embedded in a dense Nafion matrix. The reactor performance was analyzed under UV-vis light in terms of productivity, selectivity and converted carbon. Reaction pressure was specifically investigated for its effect as a "driver" in determining reactor performance, modulating products removal from the reaction volume. In addition, the membrane reactor performance was explored as a function of HO/CO feed molar ratio and contact time. The higher feed pressure (5 bar) led to a lesser MeOH production and a greater amount of HCHO, owing to a hindered desorption, which promoted partial oxidation reactions. Total converted carbon instead did not vary significantly with reaction pressure. Membrane reactor with CN-TiO photocatalyst resulted more performant than other photocatalytic membrane reactors in terms of carbon converted (61 ?mol g h).