Designer Carbon Nanotube Columns for Chemo- and Bio-Catalytic Synthesis in Flow

Lead Research Organisation: University of Oxford
Department Name: OxICFM CDT

Abstract

Hydrogenation reactions involve addition of hydrogen gas across a double bond, and account for 10-20% of all industrial chemical steps. However, industrial hydrogenation processes often rely upon precious, heavy metals which may contaminate the final reaction product. Selectivity is also a significant challenge with metal catalysts: hydrogenation may occur in unwanted positions on a complex molecule, certain substituents on the molecule such as halogens may be lost during hydrogenation, and it is very difficult to produce single enantiomer forms of chiral (mirror image) molecules during hydrogenation with metal catalysts. In contrast, enzymes isolated from natural organisms are very good at achieving these same chemical products with exquisite selectivity, and are fully biodegradable and renewable because they are isolated from cells of micro-organisms which are easy to cultivate.
Unfortunately, current methods for applying enzymes (biocatalysts) to make hydrogenated chemical products generate a lot of chemical waste which makes the processes less attractive and more costly. This is because the enzymes need expensive cofactors which must be re- charged continually during a reaction. The cofactor re-charging processes are usually powered by sugar (glucose), and most of the glucose molecule goes to waste, and may be burnt at the end of the reaction. To clean up biocatalysis, the Vincent group have developed biocatalytic strategies for driving cofactor re-charging using hydrogen gas, or avoiding the need for cofactors completely. Key themes of this research are the use of hydrogenase enzymes to oxidise dihydrogen selectively, and the use of carbon support materials for hydrogenase immobilisation. This project lies at the interface between Biocatalysis and Materials Science, and focusses on fundamental design principles for carbon materials which are suited to supporting biocatalysts for the generation of amine products.
Amines are chemical compounds defined by the presence of an NH2 functional group and are of immense industrial importance in the production of pharmaceuticals, dyes, and plastics, necessitating their production on a massive scale. The project presented herein will probe various designer carbon materials for their ability to support hydrogenases and participate in the selective generation of amine chemical products. A focus will be placed on carbon nanotubes, which are of increasing interest to the scientific community because of their tuneable electronic and chemical properties and will provide a platform for investigating the relationship between fundamental material properties and catalytic efficiency. Through optimisation and scale-up of this biocatalytic hydrogenation system, a greener, selective, and commercially feasible method for generating important amine compounds could be developed, with wide applications in research, industry, and pollutant remediation.
This project falls within the EPSRC Physical Sciences - Catalysis Research Area.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S023828/1 01/04/2019 30/09/2027
2404164 Studentship EP/S023828/1 01/10/2020 30/09/2024 Maya Landis