1. Department of Chemical Engineering, University of Malaya, Kuala Lumpur, Malaysia
2. Sustainable Process Engineering Centre (SPEC), University of Malaya, Kuala Lumpur, Malaysia
3. Department of Chemical Engineering, Ahmadu Bello University, Zaria 810222, Nigeria
4. Nanotechnology & Catalysis Research Centre, Institute for Advanced Studies, University of Malaya, Kuala Lumpur, Malaysia
5. Center for Refining & Advanced Chemicals, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia