Artificial photosynthetic architectures to promote sustainable multi electron transformations

With the continuous increase in energy demands and environmental issues associated to the use of fossil fuels, it is of high societal importance to propose alternative energy sources. The use of abundant and clean solar energy therefore appears as one attractive solution to replace fossil fuels. Nature converts and stores solar energy into chemical bonds through photosynthesis where energy from sunlight drives multi-electron catalysis, first oxidizing water in a four-electron and four-proton process and then reducing CO2 to sugars. Inspired by natural photosynthesis, researchers develop artificial systems with the ultimate goal to store solar energy into fuels or convert it into chemical feedstocks for our modern societies. Under these circumstances, utilization of solar energy to promote important chemical oxidation reactions is a highly promising approach. Still, performing light-driven multi-electron catalytic transformations efficiently represents big challenges for chemists. Some recent examples of oxidation reactions catalyzed by photo-generated metal-activated species have been reported. However, these systems used are often intrinsically limited by the requirement of high concentrations of sacrificial electron acceptors. In this project, we aim a coupling a light-triggered 2-electron oxidative process to the catalytic reduction of dioxygen (as renewable and safe electron acceptor) at a robust metalloenzyme: a fungal laccase. Our project will combine approaches including: (i) protein engineering (ii) design of photocatalytic molecular assemblies (iii) generation of hybrid architectures with selective orientation of the components at the enzyme’s surface (iv) spectroscopic and photophysical studies and (v) photocatalytic assays.