Operando study of ceria based catalysts by near ambient pressure X-ray spectroscopy

Due to the unique property of ceria to release as well as capture easily oxygen, ceria based catalysts are widely used in many important chemical reactions such as oxidation of CO, water-gas shift reactions, dry reforming of methane and CO2, etc. The detailed study of the reaction processes is important for many reasons, including the help it gives in understanding reaction mechanisms and controlling chemical reactions. Near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) makes it possible to investigate the catalyst surfaces in conditions, which are very close to the real reaction conditions. It allows direct observation of both the oxidation states of active catalyst centres and the presence of different reaction intermediates on catalyst surface during a chemical reaction. This information can give us a detailed view of processes taking place on surface of the catalyst during different important chemical reactions. Understanding elementary steps of the reaction mechanisms involved makes it possible to choose reaction conditions favouring one path over another, thereby resulting in maximum amounts of desired products and minimum amounts of undesired products.

The dissertation work will be mostly focused on preparation and investigation of physico-chemical properties of ceria supported metal catalysts M-CeO2 (M = Pt, Au, Ni, Co, etc.) in operando conditions. Together with NAP-XPS technique other powerful characterization techniques such as low energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and synchrotron radiation photoelectron spectroscopy (SRPES) are planned to be used in this work.

Literatura

1. Operando Research in Heterogeneous Catalysis, J. Frenken, I. Groot (Eds.), Springer International Publishing AG, Leiden, Netherlands, 2017, ISBN: 978-3-319-44439-0.
2. Surface Analysis by Auger and X-Ray Photoelectron Spectroscopy, D. Briggs, J. T. Grant, IMPublications, Chichester, UK and SurfaceSpectra, Manchester, UK, 2003, ISBN: 1‐901019‐04‐7.
3. Catalysis by Ceria and Related Materials, A. Trovarelli, Imperial College Press, London, UK , 2002, ISBN: 978-1-86094-299-0.