Myth busting the role of catalyst support: producing hydrogen via organic photoreforming with “inert” SiO2

Supervisory teams: Prof. Rose Amal, A/Prof Jason Scott, Dr Roong Jien Wong, Dr Cui Ying Toe

Project Descriptions: For many years, catalyst support has been assumed to be catalytically inert, having no role in catalytic reactions. However, we have recently discovered that SiO2, although inert by nature, contains Non-Bridging Oxygen Hole Centres (NBOHC), which is able to activate O2 molecules for oxidation reactions.1 The presence of NBOHC is capable of achieving oxidation rates several times higher than some common catalysts in the dark, such as TiO2. By incorporating SiO2 into TiO2, oxygen vacancies of the composite material can be stabilised, forming stable Ti3+ states and increasing the material's catalytic performance. The current project will look into the utilisation of such oxygen vacancies for sustainable H2 production from organic chemicals to simulate biomass waste, with the possibility to extend the scope to metal nanoparticle-loaded SiO2-TiO2 composite support or coupling with tandem electrochemical organic reforming system (PhD project).

Our recent results show that composite SiO2-TiO2 outperforms commercial TiO2 P25 in photocatalytic H2 generation in the presence of formic acid. The potential and capability of organic photoreforming in our laboratory for H2 production have also been demonstrated by our latest results, producing up to ~150 ml H2/gcat/h with methanol. In this project, the student will be incorporating SiO2 of various loadings into lab-made TiO2 support to manipulate the oxygen vacancy concentration. The effect of oxygen vacancy concentration (and other structural defects) on organic photoreforming mechanism will be investigated with the aid of Nuclear Magnetic Resonance Spectroscopy and Electron Paramagnetic Resonance Spectroscopy. Other characterisation techniques that the student will be exposed to include UV-Vis spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. The student will also be introduced to High Resolution Transmission Electron Microscopy and Energy Dispersive X-ray Spectroscopy characterisation techniques.
This project will contribute valuable insights towards the role of catalyst support in catalytic reactions. As this is currently a high priority project, interested students should consult the Academic staff involved on a regular basis for the latest updates prior to the commencement of the project.

Suitable for: Chemical Engineers and Industrial Chemistry students. Project maybe available to do during summer semester.

Level of difficulty: Very Challenging

For more details, please contact Professor Rose Amal (r.amal@unsw.edu.au)