<i>Operando</i> Observations for Catalysis with Soft-X-ray Surface Spectroscopy

Development of operando soft-X-ray surface spectroscopy techniques using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and ambient-pressure soft-X-ray absorption spectroscopy (AP-sXAS) and their application to operando observations for surface catalytic reactions are reviewed. First, we will explain soft-X-ray surface spectroscopy end-stations that we developed for operando observations at the Photon Factory. As for the application, we introduce studies on CO oxidation on Pt-group metals and their alloys and photoinduced carrier transfer to cocatalysts on a SrTiO3-based photocatalyst. We will also discuss future advancements of the operando soft-X-ray surface spectroscopy techniques.