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Lookup NU author(s): Abdul Rehman, Mohamad Gunam Resul, Dr Valentine Eze, Professor Adam Harvey
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2019 Rehman et al.Synthesis of styrene carbonate (SC) via the fixation of CO2 with styrene oxide (SO) has been investigated using a combination of zinc bromide (ZnBr2) and tetrabutylammonium halides (TBAX) as acid-base binary homogeneous catalysts. The combination of ZnBr2 and TBAB had a synergistic effect, which led to about 6-fold enhancement in the rate of SC formation as compared to using TBAB alone as a catalyst. Propylene carbonate (PC) was chosen as a green solvent for a comprehensive study of reaction kinetics. The reaction followed a first-order kinetics with respect to SO, CO2, and TBAB, whereas a fractional order was observed for the ZnBr2 when used in combination with the TBAB. Arrhenius and Eyring's expressions were applied to determine the kinetic and thermodynamic activation parameters, where activation energy (Ea) of 23.3 kJ mol-1 was obtained for the SC formation over the temperature range of 90-120°C. The thermodynamic analysis showed that positive values for enthalpy (ΔH‡ = 18.53 kJ mol-1), Gibbs free energy (ΔG‡ = 79.74 kJ mol-1), whereas a negative entropy (ΔS‡ =-162.88 J mol-1 K-1) was obtained. These thermodynamic parameters suggest that endergonic and kinetically controlled reactions were involved in the formation of SC from SO and CO2
Author(s): Rehman A, Gunam Resul MFM, Eze VC, Harvey A
Publication type: Article
Publication status: Published
Journal: Green Processing and Synthesis
Year: 2019
Volume: 8
Issue: 1
Pages: 719-729
Online publication date: 06/08/2019
Acceptance date: 19/05/2019
Date deposited: 28/08/2019
ISSN (print): 2191-9542
ISSN (electronic): 2191-9550
Publisher: Walter de Gruyter GmbH
URL: https://doi.org/10.1515/gps-2019-0042
DOI: 10.1515/gps-2019-0042
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