2005 Fiscal Year Final Research Report Summary
Chemical Fixation of Carbon Dioxide Using Solid Catalysts in Supercritical Carbon Dioxide
| Project/Area Number |
15560664
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Catalyst/Resource chemical process
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
FUJITA Shin-ichiro Hokkaido Univ., Grad.School of Eng., Inst., 大学院・工学研究科, 助手 (80156869)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Supercritical carbon dioxide / Chemical fixation of carbon dioxide / Solid base catalyst / Cyclic carbonate / Dimethyl carbonate / Cyclic urethane / Cyclic urea |
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| Research Abstract |
Chemical fixation of carbon dioxide (CO_2) is an important issue from the viewpoint of green chemistry. On the other hand, supercritical CO_2 (scCO_2) is an easily recyclable and environmentally benign solvent and, furthermore it can eliminate the interface between gas and liquid phases. So, the use of scCO_2 as both the solvent and the substrate may give efficient reaction systems for the chemical fixation of CO_2. The aims of the present study are to investigate the characteristics of chemical fixation of CO_2 using solid catalysts in scCO_2 and to search catalysts active for such the reaction systems.
1.SYNTHESIS OF CYCLIC CARBONATE: Several smectite catalysts were prepared and used for the reaction of CO_2 and propylene oxide. It was found that strongly basic sites whose amount depends on the alkali atoms incorporated are significant for the reaction. High CO_2 pressures are not needed to obtain high yields. Bi-functional catalyst systems of Lewis acid (ZnBr_2) and Lewis base (imida
… More
zolium salts, quaternary ammonium salts) were found to be very active. They can produce styrene carbonate under mild conditions even from styrene oxide that has very low reactivity for the reaction. The influence of CO_2 pressure is different by the catalyst systems.
2.ONE-POT SYNTHESIS OF DIMETHYL CARBONATE (DMC) : It was found that smectite catalysts can be used for the reaction of CO_2, propylene oxide and methanol to produce DMC. Strongly basic sites are significant also for this reaction. They retards the side reaction, methanolysis of the epoxide.
3.SYNTHSIS OF CYCLIC URETHANE AND UREA : CO_2 cycloaddition reactions with diamine and aminoalcohol were carried out without catalysts. Aliphatic cyclic urea was produced in excellent yields ; however, the yields of aromatic cyclic urea and both aliphatic and aromatic cyclic urethane were low. So, several solid catalysts and ionic liquids were tested for the synthesis of cyclic urethane. It was found imidazolium salts can catalyze this reaction.
4.OXIDATIVE CARBOXYLATION OF STYRENE : Tetrabutyl ammonium bromide (TBAB) was found to be a good catalyst for the production of styrene carbonate (SC) from styrene, CO_2 and organic peroxide in one-pot. It gave better SC yields than those reported so far. Combination of TBAB-ZnBr_2-Au/SiO_2 was also a good catalyst system. It could reduce the reaction time compared with TBAB alone. The SC yield was slightly improved by this tri-functional system. Less
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Research Products
(30 results)
