The Study Of Green Catalytic Process For Synthesis Of Styrene Carbonate

Carbon dioxide is the main greenhouse gas. With the increasing of the discharging of carbon dioxide as the main greenhouse gas, our life and the production have been affected. We all pay attention to make good use of the carbon dioxide under mild conditions.Styrene carbonate is used not only as excellent aprotic polar solvents but also intermediates for producing fine chemicals. Owing to its high boiling point, good biodegradability and high solvency, it can be used in the industries of degreasing process, dope cleaning, and abstersion. Therefore, SC is a kind of commercially important compound and has lots of applications.In this paper, several high-efficiency catalysts were designed and fabricated for the synthesis of SC from CO2 and styrene. Concretely, This thesis consists of the following four parts:The first part, green organic synthesis, as a new frontier of green chemistry, was reviewed which included the"green"catalysts,"green"solvent and"green"reaction process. The application of CO2 and the application and synthesis of cyclic carbonates were reviewed. Finally, we illuminated the intention and significance of this research.The second part, Vanadium and nickel acetylacetonate complex were grafted on the surface-modified carbon nanofibers and SBA-15 for styrene epoxidation and one-step synthesis of SC. The grafted vanadium and nickel acetylacetonate complex showed a good reactivity to epoxidation of styrene. The target product had a high selectivity, and the yield rate of SC was up to 51.5%, This catalyst can be renewable.The third part, the supported resin catalysts were prepared by the ion-exchange method. In the epoxidation of styrene, Co active component exhibited higher activity and selectivity than Fe active component, the yield of SO can reach 28.48%; With the increasing of Co content, the yield of SC increased quickly first and then decreased, when the mass ratio of Potassium hexacyanocobaltate (Ⅲ) to D201 is 1:4, a maximum yield of about 21.45% for SC is obtained. Meanwhile carbonizing process of metallic active component/resin was analyzed, obtaining the rule about the carbonization temperature: higher carbonization temperature can make support get higher porosity and surface area, it has been shown that the corresponding catalysts prepared by the impregnation method exhibited higher activity. The effects of reaction time, amount of catalyst, CO2 pressure have been investigated in order to obtain optimum reaction conditions. The yield of SC is stable under the conditions of 80℃, 5.0MPa CO2 pressure in 6h of reaction time, SO has a high yield and the reaction has little by-product formation. An improved styrene carbonate yield(34.99%) was obtained under mild reaction conditions of 90℃, 6h, 5.0MPa CO2 pressure and 300mg Co+/NKC-9-TBAB. CO2 pressure is not necessary for the reaction.The fourth part, the catalyst, Au/MgO and Co/MgO were prepared by dipping technique. With TBHP the catalyst systems are used in SC synthesis reaction, the results indicated that Au active component exhibited higher activity than that of Fe.Mesoporous magnesium oxide was prepared. The catalyst samples Au/MgO were prepared by impregnation using different kinds of MgO, the experimental results demonstrated that Au/MgO which used mesoporous magnesium oxide as support exhibits the highest catalytic activity, which of MgO prepared by carbonization and the purity of magnesia oxide decreased in turn. Porosity and surface area of MgO are the same order. The yield of SC can reach 41.74%. Co/MgO-TBAB and Au/MgO-TBAB were prepared by dipping with TBAB, and Au/MgO-TBAB showed higher capability in one-step reaction than Co/MgO-TBAB, the yield of SC can reach 44.71%.