FTIR study of zeolites: the nature, concentration and accessibility of the acid sites

Antunes da Silva Freitas, Cátia Manuela

Abstract

Zeolites represent one of the most important groups of industrial heterogeneous catalysts with large-scale applications in refining, petrochemistry and increasing potential in environmental catalysis and synthesis of fine chemicals. This broad range of catalytic applications comes from their unique set of acidic properties; it is therefore, vital to understand these properties.
The main aim of this doctoral thesis is the further study of the acidity properties of a variety of zeolite materials using in situ infrared spectroscopy (FTIR) in combination with different probe molecules. The focus of the work will be on the generation of accurate quantitative and qualitative analysis, and the development of new methodologies for the application of various probe molecules with different kinetic diameters and basicity. The approaches developed in this research expand upon the characterisation of the nature, number, accessibility and strength of acid sites in medium-, large- and mixed pore zeolites subject to different synthesis methods and post-synthesis modifications.
This work demonstrates the importance of cross-validation of data between characterisation techniques and significance of utilising different approaches to understand interactions between acid site and different probe molecules. This study also provides a detailed investigation on the textural, structural and acidity properties in different zeolite structures and relevant catalytic materials. The methodologies for the use of various probe molecules with FTIR presented offer a better understanding of the acid sites and their properties, in a great variety of zeolites and relevant catalytic materials.

Citation

Antunes da Silva Freitas, C. M. (2020). FTIR study of zeolites: the nature, concentration and accessibility of the acid sites. (Thesis). Keele University

• Thesis Type: Thesis
• Publicly Available Date: May 26, 2023
• Award Date: Jun 1, 2020