2007 Fiscal Year Final Research Report Summary
Solvent-free cahtic oxidation system using environmentally benign sold-disperse phase
| Project/Area Number |
17510067
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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 |
Environmental technology/Environmental materials
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| Research Institution | Osaka University |
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Principal Investigator |
ICHIHARA Junko Osaka University, Institute of Scientific&Industraial Research, Assistant Professor (60110772)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Shunro Osaka Univeasity, Institute of Scientific&Industrial Research, Assistant Professor (40167698)
SASAKI Yoh Kinki University, Faculty of Science and Engineering, Associate Professor (70205871)
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| Project Period (FY) |
2005 – 2007
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| Keywords | green chemistry / solvent-free / apatite solid-phase / epoxidation / hydrogen peroxide / recycle system / oxidation of sulfides / polyoxometalates catalysts |
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| Research Abstract |
We have recently developed a new approach to solvent-free catalytic oxidation system using `green solid disperse phase'. We studied on the solid-phase oxidation system from the view point of the enhancement of the reactivity-selectivity and the degree of green chemistry. The solvent-free catalytic epoxidation system was carried out at powdery solid-state by using dodecatungstate catalyst ((CetylPy)_<10> [H_2W_<12>O_<42>])/solid disperse phase (fluorapatite(FAp)) with a solid hydrogen peroxide (urea-H_2O_2). The solid catalyst/FAp was reusable and retained its high catalytic activity, although the catalyst was not fixed on the solid-phase. The high efficiency in the system was found to be due to a new peroxo species that retains the framework of the parent cluster with site-specific peroxo group. In a similar way, Keggin-type phosphomolybdate catalyst / FAp solid phase was a reusable solid-phase with high catalytic activity and selectivity for the oxidation of sulfides to sulfoxides. The system enables to make use the structural diversity of polyoxometalates as a catalyst. We also developed a O_2-oxidation-system using Keggin vanadomolybdophosphoric acid (H_<3+n> PVnMo_<12-n>O_<40>: PVn)/FAp. The solid-phase-system was efficiently and repeatedly used for solvent-free oxidative dehydrogenation of α-terpinene to ρ-cymene under mild conditions with 1 atm of molecular oxygen. Our solid phase system is convenient and a green process in the following points: solvent-free catalytic reaction, without heating or cooling, use of a harmless solid phase, reusable solid catalyst phase, and a simple work-up without special apparatus.
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