CO2 Cycloaddition to Styrene Oxide Catalysed by ZnBr2 Impregnated Rice Husk Ash Silica: Structural and Kinetics Studies

• Main Authors: Swee Yi, Yao, Anwar, Iqbal, Dr. N. H. H, Abu Bakar, Muhammad Rahimi, Yusop, Hariy, Pauzi, Devagi, Kanakaraju
• Format: Article
• Language: English
• Published: Wiley 2022
• Subjects: QD Chemistry
• Online Access: http://ir.unimas.my/id/eprint/40306/1/Chemistry%20select%202022%20Dr%20Devagi_Abstract.pdf; http://ir.unimas.my/id/eprint/40306/; https://chemistry-europe.onlinelibrary.wiley.com/hub/journal/23656549/overview; https://doi.org/10.1002/slct.202201970

A series of ZnBr2 impregnated on rice husk ash silica catalysts were synthesised via the wet impregnation method for the CO2 cycloaddition to styrene oxide reaction. The X-ray diffraction (XRD) analysis indicates that the impregnation resulted in the deterioration of the silica’s pore channels. Catalyst with 0.5 w/w % of Zn (0.5 wt%ZnBr2-SiO2) was highly active in the CO2 cycloaddition to styrene oxide. The conversion of styrene oxide (StO) was 89.1 %, with the styrene carbonate (SC) selectivity of 92.1% under the optimum conditions (130 °C, 60 bar, 3 h and solventless). Additionally, the universality of 0.5 wt%ZnBr2-SiO2 was also studied with other epoxides, and it shows good to excellent activity. The catalytic performance of the 0.5 wt% ZnBr2-SiO2 remains constant after being reused three consecutive times. The activation energy of the reaction was determined to be 89.06 kJ/mol.