Catalytic activity of metal clusters on surfaces

Figure shows the HR-TEM image of the Au9 cluster deposited on a titania nanosheet. Scale bar is 0.5 nm

Figure shows the HR-TEM image of the Au9 cluster deposited on a titania nanosheet. Scale bar is 0.5 nm.

For any possible application of metal clusters as catalysts it is necessary to deposit them onto surfaces. 

Therefore, it is the geometric and electronic (valence) structure of clusters at the surface that determines their interactions, and consequent reactivity, with molecules. 

We are developing techniques to determine the geometric and electronic structure of size-specific clusters (e.g. Au9) deposited onto semiconductors surfaces (e.g. TiO2) and test their performance for photocatalytic water-spitting (H2 production) and CO2 reduction (hydrocarbon formation). 

The characterisation studies involve the direct comparison between the physical and chemical properties displayed by isolated and deposited clusters to disentangle the surface effects. 

Surface characterisation is undertaken via a combination of X-ray Photoelectron Spectroscopy (XPS), Scanning Tunnelling Microscopy (STM) and Metastable Induced Electron Spectroscopy (MIES).  This also involves visits to the Australian Synchrotron to use Soft X-ray and Far-IR spectroscopies. 

Combined with quantum chemical calculations, these techniques provide information about the interaction between each size-specific cluster and the titania surface. In addition, we use ultra-high resolution Transmission Electron Microscopy to directly observe, with atomic resolution, individual clusters on the surface. 

We also experimentally measure the catalytic performance of these clusters-based systems using a specially-developed reactor systems. 

Skills to be developed include operating simulated concentrated solar sources, high vacuum pumps and gas handling and detection systems, as well as learning to undertake advanced surface electron spectroscopy characterisation techniques and atomically-resolved, high resolution electron microscopy measurements. Quantum computational calculations can also be part of this project. 

This work is done with collaborators at Flinders, Newcastle, Canterbury, (NZ), and Utah (USA) universities and could include visits to these labs.

Greg Metha


Professor Gregory Metha

Research area: Chemistry

Recommended honours enrolmentHonours in Chemistry

Tagged in Honours projects - Chemistry, Honours projects - Greg Metha