Luke Andrew
School of Mathematical and Physical Sciences
Grantham Scholar
- Profile
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Computational Modelling of photocatalytic conversion of organic molecules into biofuels.
The project:
To achieve net zero and reduce carbon emissions globally, we need to develop new energy sources, for example by replacing fossil fuels with biofuels. This project is a collaboration with experimental partners (Prof. R. Douthwaite at the University of York), focussed on photocatalytic conversion of organic molecules, such as long-chain organic acids present in cooking oils, into biofuels. Photocatalysis is an effective technique for driving chemical conversions using sunlight as the source of energy. The group in York has developed a BiVO4 -based photocatalyst, which is able to drive decarboxylation of long-chain organic acids to form alkanes. In this PhD project, we aim to understand the mechanism of this conversion and the particular role of the BiVO4 photocatalyst.
In the initial stage of the project we will model several BiVO4 surfaces and investigate the adsorption of a model carboxylic acid (acetic acid) and water at different coverages, and the adsorption of decarboxylation products (alkyl radical and CO2) on the most stable (001) crystallographic surface.
We will then investigate the mechanism of decarboxylation of the model acid, which is expected to proceed in several steps, including (i) proton-coupled electron transfer to form adsorbed carboxylate, (ii) loss of CO2 and (iii) dimerization of two alkyl radicals, as well as possible side reactions, e.g. interaction with co-adsorbed water, protonation of the alkyl radical, and incomplete decarboxylation to form alcohol or aldehyde. These investigations will be done using the climbing image nudged elastic band (CI-NEB) method. These calculations will identify the rate-limiting step in the process of conversion of carboxylic acids to long-chain alkanes. The results will be shared with experimental partners.
Publications:
"Formylation–Decarbonylation Relay Strategy for the Selective Hydrogenation of CO2 to CO" - ACS Catal. 2026, 16, 3, 2309–2317