Mapping the Structure and Chemical State of Nanoparticle Catalysts for Sustainable Reactions.
Energy Materials Interfaces Group
Catalyst nanoparticles are key to the development of sustainable technologies, including the production of hydrogen by water splitting and the conversion of carbon dioxide into useful products. They offer a high density of low-coordination sites, which can enhance interactions with adsorbing molecules helping to increase the rate at which desired products are produced. Understanding the nature of these active sites and how they promote particular reactions is essential to the designing the low-cost, earth-abundant catalysts needed to enable society’s transition to net-zero.
Nanoparticles characterisation has traditionally focussed on local high-resolution imaging of a few small particles by electron microscopy, or observing averaged chemical information using techniques such as X-ray Spectroscopy. Whilst separately these can provide valuable insights, to fully understand the role of the different active sites present on nanoparticle catalysts a more direct connection between these approaches is required.
This project aims to employ advances in large-area atomic resolution electron microscopy to better understand the behaviour of populations of catalyst nanoparticles, when used for important sustainable reactions. There will be an opportunity to develop machine-learning approaches for classifying the different active sites observed in reactions such as oxygen evolution or carbon dioxide reduction. This will then be used in interpreting operando soft X-ray absorption spectroscopy (XAS) studies, where the behaviour of the different classes of active sites will be related to the averaged spectroscopic changes observed. Electron Energy Loss spectroscopy will provide a direct link between the different active sites identified, and how these chemically evolve under reaction conditions.
Through this project, you will gain experience in advanced techniques including the preparation of size-selected nanoparticles, electron microscopy, X-ray spectroscopy, and related analysis. This will make use of state-of-the-art capabilities in Oxford, as well as the national electron microscopy and synchrotron facilities at the nearby Diamond Light Source. There is significant scope within the project to focus on certain areas, whilst collaborating with others in the research group to connect your findings with other ongoing research.
