Interfacial Photoreduction of Supercritical CO2 by an Aqueous Catalyst

摘要

Carbon dioxide (CO2) emissions currently represent a major concern. Accordingly, the electrochemical reduction of CO2 is a reaction of major relevance and also of great challenges. Considering the redox potentials required for reducing CO2, multi-electron-transfer, multiproton reactions are the most viable pathways for driving CO2 reduction. Nonetheless, catalysts must be employed to overcome kinetic limitations of these processes. Molecular catalysts known to reduce CO2 are usually monomeric metal complexes, such as ruthenium and rhenium carbonyl complexes, cobalt and iron porphyrins, and nickel and cobalt cyclams, but combinations of these systems into bimetallic structures have also been proposed. More recently, the introduction of supercritical CO2 (scCO2) as a reaction medium has been investigated, as comprehensively reviewed by Fujita and co-workers. Interestingly, it has been observed that increasing the CO2 pressure in the reaction medium usually does not provide any advantage.