Ambient pressure spectroscopic investigation of the catalyst – support interface

We are looking for a talented and motivated student to join an exciting joint project between Imperial College London and the Diamond Light Source. The studentship will focus on spectroscopic characterisation of catalysts, materials that enable chemical reactions to happen more quickly, and with a lower energy requirement. The project will entail careful measurement of catalysts as they operate, using state-of-the-art equipment located at both Imperial College, in central London, and at Diamond, located just south of Oxford. The studentship will also be integrated within the EPSRC-funded Centre for Doctoral Training in Advanced Characterisation of Materials.

Understanding catalysts is a crucial area of materials science, and precious-metal nanoparticles supported by metal oxides are widely used in heterogeneous catalysis, such as Au/TiO2 and Pt/CeO2 for carbon monoxide oxidation. It has been long thought that the metal particles act alone as the catalyst while the oxide supports only serve to disperse the particles. Recent experimental evidence [1,2], however, points at the metal/metal-oxide interfaces, rather than the under-coordinated metal sites at the surfaces of the nanoparticles, being where the most catalytic activities occur. It has been suggested that gold cations may break away from the gold particles to form isolated active sites. Highly reactive “single-atom catalysts” can hence be realised if such reaction centres can be prepared in high density on the surface of an oxide support.

The purpose of the PhD will be to study how simple molecules interact at this single-atom–support interface using both ex-operando ultra-high vacuum (UHV) and in-operando ambient pressure (AP) conditions. Over the last two decades leaps and strides have taken place in the development of ambient pressure electron energy analysers, which now allow photoelectron experiments to take place in pressures of a millibars instead of the usual 10-10 mbar (UHV regime). This allows any technique that requires the detection of photoelectrons to be utilised in in-operando conditions. We will utilise the world-leading laboratory-based ambient pressure XPS system at Imperial College London, and combine this with highly precise quantitative structural information about this interface exploiting ex-operando energy scanned photoelectron diffraction (PhD) and X-ray standing waves (XSW) at the I09 beam line (Diamond Light Source) and in-operando ambient pressure energy scanned photoelectron diffraction (AP-PhD) at the B07 beam line (Diamond Light Source). This work will provide a deep insight, at an atomistic level, into heterogeneous catalysis and offer precise quantitative information for comparison to theoretical calculations.

For more information please contact Dr. David Payne ([Email Address Removed]) including your CV and cover letter.