Development of metal-‎free catalysts for the synthesis of cyclic ‎carbonates from CO2‎

The aim of this work that led to this thesis was to design and develop metal-free catalytic ‎systems that can catalyse the reaction of CO2 with epoxides to produce cyclic carbonates as ‎the main target product under mild conditions (e.g. low temperature and low CO2 pressure). ‎The ideal catalytic system should be synthesised through a simple, low-cost procedure, ‎display high catalytic performance, good recyclability, and easy separation from the reaction ‎products. Besides, the development of the new cyclic carbonates products was a further aim ‎of this work. The catalytic systems developed in this PhD project achieved improved ‎performance compared to the state-of-the-art catalysts for the synthesis of cyclic carbonates ‎from CO2. Two classes of metal-free catalytic systems were studied for the CO2/epoxide ‎reaction in this thesis. The first class is a homogenous catalytic system, which is based on ‎organic halide in the presence of water as a hydrogen bond donor. The second system is a ‎heterogeneous catalyst consisting of Amberlite ion-exchange resin, which is used in ‎combination with water as HBD (chapter 3). The Amberlite ion-exchange resin is further ‎studied without using water for the one-pot conversion of CO2 into glycerol carbonate ‎‎(chapter 4). Finally, a summary of the main achievements of the PhD thesis on the synthesis ‎of cyclic carbonate from CO2 and epoxide is highlighted in chapter 6. ‎