Electronic structure and local atomic environment of Re species on a TiO2 support under catalytic conditions (water, temperature, and H2 pr

We have demonstrated that rhenium is an effective alternative to noble metals for the selective hydrogenolysis of erythritol to valuable butanediols (“target polyols”). A key challenge, however, is to determine the oxidation state of Re during the catalytic process. Using high-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD-XAS) under catalytic conditions, i.e., in the presence of water and erythritol at 240 °C and 120 bar of H2, we want to identify the nature of the active species. The rhenium catalysts used during the previous experiments at ESRF (A16-1-843) were unfortunately fully oxidized due to the storage for a few days. Therefore, the new experiments will aim to characterize the electronic structure and local environment of Re species under working conditions using freshly reduced catalysts, to determine the actual oxidation states of Re during the reaction. For that, the catalysts will be reduced in situ, directly at ESRF, before the reactions.