Catalytically Active Materials Visualized by Scanning Photoelectron Spectro-Microscopy

Abstract

Modern catalysts are complex systems whose performance depends both on space and time domains and, most importantly, on the operational environment. As a direct consequence, understanding their functionalities requires sophisticated techniques and tools for measurement and simulation, addressing the proper spatial and temporal scale and being capable of mimicking the working conditions of every single component, such as catalyst supports, electrodes, electrolytes, as well as of the entire assembly, e.g., in the case of fuel cells or batteries. Scanning photoelectron spectro-microscopy (SPEM) is one of the approaches that allow combining X-ray photoelectron spectroscopy with sub-micron spatial resolution; in particular, the SPEM hosted at the ESCA Microscopy beamline at Elettra has been upgraded to conduct in situ and operando experiments. Three different case studies are presented to illustrate the capabilities of the SPEM in the investigation of catalytic materials in different conditions and processes.

Keywords

• heterogeneous catalysis
• scanning photoemission microscopy
• XPS
• ORR
• metal particles