Gas-phase models of cluster-surface interactions

Greg Metha - Zeke Spectrum

Figure shows the simulated Neutral - Cation electronic absorption spectra of Au bound to Ce2O (i.e. the Au-Ce2O bi-cluster) compared to the experimental PIE spectrum.

The electronic and geometric structures are key pieces of information that are necessary to gain understanding of any cluster-surface interaction. 

For clusters where quantum effects dominate, the electronic structure can change significantly when a single metal atom is added or subtracted. Since the electronic structure is strongly linked to the geometric structure, changes in geometry can also be expected when the cluster size is altered. 

However, this information is extremely difficult to extract by only investigating clusters deposited on surfaces. 

By combining accurate laser-based photo-ionisation efficiency (PIE) spectroscopy with state-of-the-art computational methodology, we can determine the local geometric and electronic structures of metal clusters bound to model metal-oxide ‘surface’ clusters. 

Our current and emerging work is focused on Au, Rh and Pt clusters bound to cerium-oxide and titanium-oxide clusters, which are all important surfaces for catalytic oxidation reactions. The measured spectrum for each 'bi-clusters' yields quantitative information about the electronic charge transfer between the cluster and metal-oxide support. The theoretical calculations are directly compared against the experimental values to provide valuable benchmarking data to enable more complicated calculations on bulk (real life) metal-oxide surfaces. 

In this honours project, skills in operating high energy lasers, high vacuum pumps and high voltage power supplies will be developed as well as learning to undertake advanced quantum computational calculations and simulations. This work is done with collaborators at the University of Tokyo and could include student visits to work overseas.

Greg Metha

Supervisor

Professor Gregory Metha

Research area: Chemistry

Recommended honours enrolmentHonours in Chemistry

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