Regulation of Redox Molecular Junctions in Covalent Organic Frameworks for H2O2 Photosynthesis Coupled with Biomass Valorization.

The H2O2 photosynthesis coupled with biomass-valorization can not only maximize the energy utilization but also realize the production of value-added products. Here, a series of COFs (i.e. Cu3-BT-COF, Cu3-pT-COF and TFP-BT-COF) with regulated redox molecular junctions have been prepared to study the H2O2 photosynthesis coupled with furfuryl alcohol (FFA) photo-oxidation to furoic acid (FA). Best of them, the FA generation-efficiency of Cu3-BT-COF can be 575 mM g-1 (conv. ~100% and sele. >99%) and meanwhile the H2O2 production-rate can reach up to 187,000 μM g-1, much higher than Cu3-pT-COF, TFP-BT-COF and its monomers. As proved by theoretical calculations, the covalent coupling of Cu cluster and thiazole group can promote the charge-transfer, substrate-activation and FFA-dehydrogenation, thus boosting the both kinetics of H2O2 production and FFA photo-oxidation to increase the efficiency. This is the first work about COFs for H2O2 photosynthesis coupled with biomass-valorization, which might facilitate the exploration of porous-crystalline-catalysts in this field.