In situ EPR spectroscopy proved to be a versatile tool to identify active sites for photocatalytic hydrogen generation in modified Y2Ti2O7 and CsTaWO6 catalysts of pyrochlore structure, in which the metal cations are located in two different positions A and B. It was found that the B-sites exclusively occupied by titanium (Y2Ti2O7) and tantalum/tungsten (CsTaWO6) act as electron traps on the surface. From these sites, electron transfer to the co-catalysts proceeds. Thus, the B-sites are responsible for photocatalytic water reduction.
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This work has been supported by the German Science Foundation (DFG, WA 1116) and the Evonik Degussa GmbH (part-financed by the State of North Rhine-Westphalia and co-financed by the European Union Investing in our Future, European Regional Development Fund).
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Hollmann, D., Merka, O., Schwertmann, L. et al. Active Sites for Light Driven Proton Reduction in Y2Ti2O7 and CsTaWO6 Pyrochlore Catalysts Detected by In Situ EPR. Top Catal 58, 769–775 (2015). https://doi.org/10.1007/s11244-015-0415-8
- Electron transfer