1. Group Technology, Sasol South Africa (Pty) Ltd., P.O. Box 1, Sasolburg 1947, South Africa
2. Catalysis Institute, Department of Chemical Engineering, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
3. Centre for HRTEM, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa
4. School of Materials, University of Manchester, Sackville Street, Manchester, M13 9PL, U.K.
5. Sasol UK, Purdie Building, North Haugh, St Andrews KY16 9ST, U.K.
6. School of Chemistry, University of the Witwatersrand, Private Bag 3, PO Wits, Johannesburg 2050, South Africa