Solar driven CO reduction with a molecularly engineered periodic mesoporous organosilica containing cobalt phthalocyanine.

A molecular cobalt phthalocyanine (CoPc) catalyst has been integrated in an ethylene-bridged periodic mesoporous organosilica (PMO) to fabricate a hybrid material, CoPc-PMO, that catalyses CO reduction to CO in a photocatalytic system using [Ru(bpy)] (bpy = 2,2'-bipyridine) as a photosensitizer and 1,3-dimethyl-2-phenyl-2,3-dihydro-1-benzo[]imidazole (BIH) as an electron donor. CoPc-PMO displays a Co-based turnover number (TON) of >6000 for CO evolution with >70% CO-selectivity after 4 h irradiation with UV-filtered simulated solar light, and a quantum yield of 1.95% at 467 nm towards CO. This system demonstrates a benchmark TON for immobilised CoPc-based catalysts towards visible light-driven CO reduction.