The model catalytic system is a very well-defined structure, ideally with an atomically defined morphology, which in some way models the structure of a real catalyst and makes it possible to study catalytic reactions in determined conditions. Model catalysts are usually prepared as epitaxial thin films of oxides or metals on suitable single-crystal substrates. Their surfaces can be purposefully structured or transformed at the atomic level. Very often, model catalysts are systems where the catalytically active material is dispersed on the surface of oxide support in the form of metal clusters with a size in the order of nanometers. Supported metal clusters have been the subject of interest for many years by many prestigious scientific groups. Especially intensively studied are the systems containing individual atoms of active metals that maximize the use of rare metals by exposing each metal atom to reactants.
To establish a correlation between structure and catalytic performance and to understand the mechanism of the catalytic reaction at the molecular level, it is essential to obtain information on the electronic and geometrical structure of the catalyst at the surface, in bulk, and in the subsurface regions during the reaction. It is an important and challenging task because the structure of the catalyst can change in a complex way along with changes in reactant pressures and catalyst temperature, which in turn affects the reaction mechanism.
In this work, we propose to study nanostructures supported on CeO2 under in situ/operando conditions of various industrially important catalytic reactions (oxidation of CO and volatile organic substances, water-gas-shift reaction, catalytic transformation of methane and ethane into more complex valuable chemicals) using a unique combination of two state-of-the-art experimental techniques: high-pressure X-ray photoelectron spectroscopy (NAP-XPS) and high-pressure scanning probe microscopy (NAP-SPM). The research subject will be nanoclusters of Ru, Fe, and Zr which will be studied before, after, and directly during the catalytic reactions.
This project aims to determine the role of different active sites on cerium oxide-supported nanostructures when interacting with small molecules under operational conditions.