X-Ray Absorption Spectroscopy (XAS): XANES and EXAFS

Abstract

In this chapter, we review recent developments in the application of operando X-ray absorption spectroscopy (XAS) and look forward to how the outcomes of present synchrotron upgrades might extend, enhance, or otherwise affect such studies. We will consider some recent developments in beamline, detector technology, cell designs, and experimental arrangements, which are bringing new capacity to operando XAS studies and extending them into new areas of catalysis. Specific emphasis will be placed on developments in operando XAS as applied to electro-catalysis and photocatalysis, along with the different challenges that they present, and we will, in some cases, also consider methodological developments in related fields. We shall also investigate how operando research is venturing into the spectroscopically rich “soft X-ray” (sub ca. 2 keV) regime. Lastly, we shall consider the rise of laboratory XAS spectrometers and assess their role in making new types of operando study possible and how they may fit into the wider picture of operando XAS resources.