2004 Fiscal Year Final Research Report Summary
Preparation of environmental benign nano-structured catalysts composed of clay and metal complexes
| Project/Area Number |
15550137
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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 chemistry
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| Research Institution | CHIBA UNIVERSITY |
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Principal Investigator |
SHIMAZU Shogo CHIBA UNIVERSITY, FACULTY OF ENGINEERING, PROFESSOR, 工学部, 助教授 (10178957)
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| Project Period (FY) |
2003 – 2004
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| Keywords | clay minerals / intercalation / molecular recognizing catalysts / solid state NMR / nano-complexes / green catalysts / self-assembly / porphyrin complexes |
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| Research Abstract |
Novel nano-structured composites were synthesized from clays and pillar complexes with long alkyl spacers by simple cation exchange methods, where pillar complexes were rhodium(I) bipyridines and cobalt porphyrins derivatives.
The nano-structured clays were characterized by FT-IR,XRD,SEM,TEM and high-resolution solid state NMR. The loading amount of pillar complexes into LiTN was detected by CHN analysis, UV-vis, and TG-DTA. The powder XRD measurements revealed that the basal spacing of the nano-structured clay was expanded after the intercalation. The modified taeniolites with long alkyl chains (n>7) showed sharp diffraction peaks comparable to the original taeniolite. The high crystallinity of clay layers can be achieved by the hydrophobic interaction of alkyl groups in the layers. The C.S.(clearance space=basal spacing (d_<001>)-thickness of layer (0.96 nm)) of the nano-structured clays calculated from XRD increases in proportional to the length of alkyl groups (slope : 0.14 nm/CH_2). The interlayer space estimated from TEM image of the nano-structured clays is well consistent to the C.S.calculated from the powder XRD measurement. High-resolution solid-state ^<13>C NMR study for nano-structured clays elucidated the conformation of the pillar complexes in the clay to be all-trans.
Synthesized pillar complexes and nano-structured clays were used for the catalytic hydrogenation reactions and epoxidation of olefins. In case of pillar complexes, catalytic activity was decreased with increasing the alkyl chain length except for [Rh(COD)C23-bpy]ClO_4. On the contrary, the activity of the nano-structured clays increased with C.S.of the nano-structured clays. Moreover, shape selectivity of the substrate was observed fro the nano-structured clays and the interlayer space was clearly related to the stereo selectivity. Furthermore, we found that nano-structured clays were recyclable catalysts in hydrogenation.
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