Photocatalytic Oxygen Transfer as an Innovative Route for N2O Upgrading**

Abstract

As concentration of nitrous oxide (N2O) keeps growing steeply in the atmosphere, upgrading this anthropogenic greenhouse gas as a potential oxygen transfer agent constitutes a real challenge to limit global warming and ozone layer depletion. Decomposition of N2O is mainly described under highly energy-consuming thermal activation, owing to its high stability and large activation barrier, making it kinetically inert. Herein, we demonstrate the controlled photocatalytic upgrading of N2O as an oxygen atom donor, releasing only dinitrogen (N2) as a benign co-product. The doped Ag@TiO2 photocatalyst specifically activates N2O for controlled oxidation of phosphines avoiding mineralization, under mild conditions (room temperature, 1 atm, λ=365 nm), as a proof-of-concept of the valorization of N2O as an oxygen transfer agent. The catalytic system is active and selective in various organic solvents, as well as innovatively in water, depending on the phosphine structure.