1. Catalysis Science and Technology Research Centre, Faculty of Science; Universiti Putra Malaysia; 43400 UPM Serdang Selangor Malaysia
2. Department of Chemistry, Faculty of Science; Universiti Putra Malaysia; 43400 UPM Serdang Selangor Malaysia
3. Curtin Sarawak Research Institute; Curtin University; 98009 Miri Sarawak Malaysia
4. Sime Darby Research; 42960 Carey Island Selangor Malaysia