1. Department of Chemical Engineering, Catalysis Institute, University of Cape Town, Cape Town 7700, South Africa
2. Centre for Materials Engineering, Department of Mechanical Engineering, University of Cape Town, Cape Town 7700, South Africa
3. Electron Microscopy Centre, Innovation Campus, University of Wollongong, Wollongong, NSW 2517, Australia
4. Department of Chemical Engineering, University of South Africa, Florida Campus, Johannesburg 1710, South Africa
5. Department of Physics, University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa
6. Applied Electrochemistry & Catalysis (ELCAT), University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium