Study On The Green Heterogeneous Catalysts Of M-TiO2for The Synthesis Of Cyclic Carbonates

The growing attention of carbon dioxide is partly responsible for the greenhouse effect and climate change, while CO2is also regarded as an inexpensive, non-toxic and renewable carbon resource. As a result, the efficient transformation of CO2into useful chemicals is an attractive research area. One of the most promising ways is coupling of CO2and epoxides for cyclic carbonates. In this article, we designed and synthesized metal ions doped TiO2nano-particals as heterogeneous catalysts for the cycloaddition reaction of CO2to epoxides, the content was consist of three parts:Chapter1:Numbers of catalysts have been developed for the synthesis of cyclic carbonates from epoxides and CO2, these catalysts could be classified into homogeneous catalysts and heterogeneous catalysts. In view of this classification, these coupling reactions and the new achievements in recent years were simply concluded.Chapter2:Metal ions doped TiO2(M-TiO2, M=Zn2+, Cu2+, Co2+, Mn2+, Ni2+) nano-particals have been fabricated as heterogeneous catalysts for the coupling reaction of CO2and epoxides with TBAI as co-catalyst under solvent-free condition, exhibiting high catalytic activities. The effects of CO2pressure, reaction temperature and reaction time were investigated. The zinc-TiO2catalyst can be reused five times without significant loss of catalytic activity.Chapter3:Some cyclic carbonates were synthesized by constant bubbling CO2into the reaction mixture with metal ions doped TiO2as catalysts and TBAI as co-catalyst under solvent-free condition. This method reduced requirements of reaction conditions and reaction device. The effects of reaction temperature and reaction time in the presence of zinc-TiO2/TBAI catalyst system were investigated. The recyclability of zinc-TiO2was also indagated.