Active Sites for Light Driven Proton Reduction in YTiO and CsTaWO Pyrochlore Catalysts Detected by In Situ EPR.

In situ EPR spectroscopy proved to be a versatile tool to identify active sites for photocatalytic hydrogen generation in modified YTiO and CsTaWO 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 (YTiO) and tantalum/tungsten (CsTaWO) 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. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]