Imperial College London

Professor Tom Welton

Faculty of Natural SciencesDepartment of Chemistry

Professor of Sustainable Chemistry



+44 (0)20 7594 5763t.welton Website




601AMolecular Sciences Research HubWhite City Campus





Sustainable or Green Chemistry aims to make the chemicals and related industries both environmentally and economically sustainable.

I am interested in using an exciting class of solvents - ionic liquids - to improve chemical processes. I have worked with ionic liquids throughout my research career. Recently, interest from both academic and commercial chemists in these has increased dramatically. I hope that my work has made a significant contribution to this change in attitude. My research covers a broad range of the chemical sciences and I have been the author of papers in all three of the traditional branches of the subject (Inorganic, Organic and Physical). My work includes both fundamental and applied studies.

My applied research is currently focused on clean synthesis and the processing of biomass-derived polymers into materials to replace petrochemical-based plastics. The aim of this research is to understand how different ionic liquids can influence the reaction process. I also aim to use this understanding to provide more effective chemical processes by the matching of the reaction with the optimum reaction environment. We are also interested in how changing the ionic liquid an processing conditions changes the material properties of the product. We conduct much of this research in collaboration with members of the Faculty of Engineering. 

I am also interested in understanding the fundamental properties of ionic liquids. we address questions such as: why do these salts melt at such low temperatures; how do the structures of their ions lead to properties such as low viscosity? how do interactions between ionic liquid ions affect their physical properties.

We link our fundamental and applied research by investigation the effects of ionic liquids on the rates of reactions. Similar kinds of interactions that occur between the ions of the ionic liquids can occur between ionic liquid ions and solute species. We have demonstrated how these interactions can change the rates of reactions in ionic liquids.

I am currently seeking PhD students and collaborators in the following areas:

The structure and properties of ionic liquids and their mixtures (organic synthesis, spectroscopy, physical chemistry).

The processing and recycling of natural and synthetic polymers using ionic liquids (synthesis, reaction processes).

Supporting your career development

Your career is important to me. Whether your hopes are to become an academic or to go into industry, I will support your aspirations. I strongly encourage you to take advantage of all of the personal development opportunities that are on offer, particularly those that lead to professional recognition, e.g. membership of the Royal Society of Chemistry. I will make time for you during your studies, or employment, with me so that you can to take up these opportunities.

Selected Publications

Journal Articles

Niedermeyer H, Hallett JP, Villar-Garcia IJ, et al., 2012, Mixtures of ionic liquids, Chemical Society Reviews, Vol:41, ISSN:0306-0012, Pages:7780-7802

More Publications