ABSTRACT
X-ray absorption spectroscopy (XAS) represents a powerful and versatile tool for studying the electronic and atomic structure of matter on a local scale: in principle, the sample can be in any aggregation state and it applies to any element. In most cases, stability consists of recording several XAS spectra by scanning the focused beam at fixed energy in a grid of predefined mesh over the area. This chapter introduces the fundamentals of XAS and of spectra elaboration and guide the reader in the application of XAS to electrochemistry, including the basic principles and examples on how to build an electrochemical cell for in situ and operando XAS experiments. Metal nanoparticles represent an ideal system for the employment of in situ electrochemical XAS, given both the high ratio of surface to bulk atoms and the importance that they have been gaining in all fields of electrochemistry. XAS data analysis is a complicated procedure that involves several steps.
