Catalysis is at the core of many modern clean energy technologies such as fuel cells and automotive (car) catalysts, and metallic nanoparticles from precious metals are used as catalysts. A major research challenge is to find ways to reduce the weight of precious metal used in each device while at the same time maximising its activity and lifetime. Computational chemistry has a big role to play in this area. Methods such as first principles quantum mechanical calculations can be used to simulate the electronic properties and structure of nanoparticles and the chemical reactions that take place on their surfaces. Such simulations can provide unique insights at the level of electrons and atoms which can be used to understand how to develop better catalysts.
Industrially relevant metallic nanoparticles consist of hundreds to thousands of atoms. Such large numbers of metal atoms are beginning to be possible to simulate on supercomputers with recent advances in computational quantum theory such as the methods within the ONETEP program which is developed in the group of Professor Skylaris. Using this approach we will have the opportunity to model for the first time chemical reactions in the important nanoparticle size regime of 1-10nm where the transition from "nanoparticle" to "bulk metal" occurs. This PhD project will involve using simulations to investigate and understand how the size, shape, and surface of metallic nanoparticles affect the adsorption of small molecules that are involved in key catalytic processes. Subsequently chemical reactions on the surface of the nanoparticles in industrially important catalytic cycles, such as the oxygen reduction reaction in fuel cells, will be investigated. This will allow us to understand how the electronic interaction of the reactants with the nanoparticle results in particular reaction mechanisms, and to obtain information that can be used to design better catalysts. The environment, such as the surface on which the nanoparticle is anchored, and the solvent, has a strong effect on the electronic properties of the nanoparticle and will also need to be investigated using suitable multiscale simulation approaches. Some method development will also be involved in this project to enhance the simulation techniques that will be used.