Towards Rational Understanding of the Fe-quarterpyridine-mediated CO2 Reduction to Solar Fuels

The reduction of atmospheric CO2 to useful chemicals and fuels has been established as one of the most promising, clean and renewable alternatives to fossil fuels. Although the field has grown enormously during last years, information regarding mechanism and transient intermediates formed during the catalysis is still limited.TRUSol aims to explore the mechanism and the factors that control catalytic performance through the rational design of ligands and spectroscopic studies. With this goal in mind, we develop a strategy to synthesize a novel family of Fe-based quarterpyrine-based CO2 reduction catalysts. The new complexes will be tested photocatalytically, combining the molecular catalysts with mesoporous carbon nitride (mpg-C3N4) as semiconductor. The comparison of the complexes with fine-tuned ligands in regard to redox properties and photocatalytic activities will help to elucidate key aspects that govern kinetics and thermodynamics under turnover conditions. Complexes will first be explored under steady state and operando conditions by using a spectroscopic tool-kit including EPR, Mössbauer, X-ray absorption and emission spectroscopy to shed light on the electronic structures. Then, taking advantage of the ability of synchrotron techniques to selectively irradiate the metal center, laser/X-ray pump/probe time-resolved X-ray absorption and emission spectroscopy will investigate the highly reactive and/or short-lived transient intermediates in ps-ns time scales. TRUSol will put the fellow in a perfect position to achieve his career goal, a tenure track position in academia, through transferable skills such as project management, and scientific and personal training actions of the project. This interdisciplinary project promises a valuable mechanistic understanding to set the foundation of the rational design of future powerful CO2 reduction catalysts.