Imperial College London

Professor Tom Welton

Faculty of Natural Sciences

Dean of the Faculty of Natural Sciences



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




Ms Mary Scott +44 (0)20 7594 5477




305Faculty BuildingSouth Kensington Campus





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

Sustainable Development has been defined by the UN Millennium Goals as development that meets the needs of the present generation without compromising the ability of future generations to meet their needs. Sustainable Chemistry is the implementation of sustainable development in the production and use of chemicals (i.e., Green Chemistry) and the application of chemistry and chemical products to enable sustainable development. Its aims are:

  • To maintain and spread the benefits of modern chemistry and chemical products to all.


  • Using less stuff - To consume nature's resources at a rate that is lower than that at which they can be naturally replenished.
  • Making less waste - To produce waste at a rate which is less than that at which it can be naturally remediated.

It encompasses a range of activities, such as sourcing chemicals from renewable resources and/or making chemicals processes more efficient in energy and less wasteful in materials.

I am interested in using solvents 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. I also work with other solvents, e.g. siloxanes, PEG's and solvents from renewable resources, all with a view to the development of sustainable solvent technologies. 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). I am particularly interested in clean synthesis and catalysis.

The central academic aim of my research is to understand the role that the immediate chemical environments in which reacting species find themselves 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. The principal foci of my investigations are the reactions themselves and how they change in rate, product distributions etc. My group correlates our synthetic results with calculated values (e.g. gas phase acidities) and physical measurements (e.g. the spectra of probe dye molecules).

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

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

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