Structural characterisation studies during synthesis of industrial mixed metal oxide catalysts

Authors: M. Hammerton (University of Amsterdam)
Co-authored by industrial partner: No

Type: Thesis

State: Published (Approved)
Published: April 2021

Abstract: Mixed metal oxides are important catalysts in industrial processes that transform bulk hydrocarbons into useful intermediates and products. The oxygen lattice is uniquely able to facilitate redox reactions by rapidly transporting reactive species between active sites. The bulk structure of the lattice governs the availability of electrons, the reactivity of oxygen, and hence the efficiency of catalytic processes. An in-depth understanding of catalyst structure and formation mechanisms is therefore key to the development of effective catalysts. The study of relatively simple oxides gives fundamental knowledge that cannot always be applied to the more complex mixed metal oxide systems that are patented and put into use industrially. The goal of this research is to apply fundamental techniques to complex, commercial catalysts, under industrially relevant conditions, and systematically make sense of the complexity. A range of characterisation techniques that probe different aspects of catalyst structure are used in this thesis during catalyst synthesis to follow (re)organisation pathways of mixed metal oxides and identify the different structures that form. Two mixed metal oxide systems were chosen for investigation: a Cu-spinel based hydrogenation catalyst and a Mo oxide selective oxidation catalyst. The structural transformations during different synthesis steps were analysed using X-ray Absorption Spectroscopy (XAS), X-ray Diffraction (XRD), Infrared (IR), and Raman spectroscopy. New insights into both catalyst systems are discussed and several approaches to catalyst characterisation on different length scales are demonstrated to deliver a holistic understanding of catalyst synthesis.

Subject Areas: Chemistry

Instruments: B18-Core EXAFS , I20-Scanning-X-ray spectroscopy (XAS/XES)

Added On: 20/04/2021 09:38

Discipline Tags:

Catalysis Inorganic Chemistry Physical Chemistry Chemistry

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS) X-ray Absorption Near Edge Structure (XANES)