The application of ATR-IR for the in-situ investigation of heterogeneous liquid-phase hydrogenation reactions

McPake, Erin G. (2025) The application of ATR-IR for the in-situ investigation of heterogeneous liquid-phase hydrogenation reactions. PhD thesis, University of Glasgow.

Abstract

The ability to successfully probe reactions in situ is an invaluable tool to uncover the identity of the species present during reaction. Heterogeneous catalysis allows reactions to be performed in an efficient manner, with metal-based catalysts facilitating an extensive number of industrial reactions with some 95% of all chemicals in industry utilising catalysis in their process and of which 80% are heterogeneously catalysed.

Obtaining useful information regarding reactions as and when they happen can pose challenges to researchers, with spectroscopic means leading the way for in-situ investigations. Infrared spectroscopy has been used as an analytical tool for many decades and provides invaluable information concerning chemical identification, namely through functional group elucidation owing to the characteristic vibrational character of chemical bonds. Traditional methods of infrared sampling experience pitfalls when it comes to probing heterogeneous reactions, particularly three-phase reactions where there is significant perturbation from the reaction solvent. Therefore, methods such as attenuated total reflection infrared spectroscopy (ATR-IR) are applied to circumvent these issues and allow researchers to obtain information about both surface and solution phase species.

The application of ATR-IR is explored herein with the aim of showcasing the technique’s success in providing in-situ insight into hydrogenation reactions. Specifically, three distinct hydrogenation reactions are examined: (1) benzaldehyde; showcasing adsorbed and solution phase reactant partitioning (2) nitrobenzene; highlighting the importance of understanding how to achieve appreciable turnover within confined ATR reactors and (3) furfural; uncovering catalyst active sites in-situ. Each hydrogenation reaction uncovered considerations to be made regarding the use of ATR-IR for in-situ analyses and provided evidence for the advantageous application of ATR-IR in the field of heterogeneous catalysis.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: Q Science > QD Chemistry
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Funder's Name: Engineering and Physical Sciences Research Council (EPSRC)
• Supervisor's Name: Gibson, Dr. Emma and David, Professor Lennon
• Date of Award: 2025
• Depositing User: Theses Team
• Unique ID: glathesis:2025-85629
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 01 Dec 2025 10:28
• Last Modified: 01 Dec 2025 10:32
• Thesis DOI: 10.5525/gla.thesis.85629
• URI: https://theses.gla.ac.uk/id/eprint/85629