1992 Fiscal Year Final Research Report Summary
Molecular Design and Structural Controlling of Heterogeneous Reaction Sites by Ship-in-bottle Synthesis
| Project/Area Number |
03453001
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理化学一般
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| Research Institution | Hokkaido University |
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Principal Investigator |
ICHIKAWA Masaru Hokkaido Univ., Catalysis Research Center, Professor, 触媒化学研究センター, 教授 (70176288)
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| Co-Investigator(Kenkyū-buntansha) |
OHNISHI Ryuichiro Hokkaido Univ., Catalysis Research Center, Research Associate, 触媒化学研究センター, 助手 (30001720)
SHIDO Takafumi Hokkaido Univ., Catalysis Research Center, Research Associate, 触媒化学研究センター, 助手 (70235539)
FUKUOKA Atsushi Tokyo Univ. of Agriculture and Technology, Faculty of Engineering, Assistant Pro, 工学部, 講師 (80189927)
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| Project Period (FY) |
1991 – 1992
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| Keywords | Ship-in-bottle Synthesis / Heterogeneous Reaction Sites / Molecular Design / Reaction Control |
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| Research Abstract |
Metal carbonyl clusters grafted on supports such as oxides and zeolites offer a great advantage in the rational preparation of metal/bimetal ensemble sites for activation of small molecules such as CH_4,CO_2 and H_2O to be effectively converted into useful chemicals. Metal clusters entrapped in zeolite micro-pores are ideal objects for the study of collective behavior and heteronuclear two-site promotion in stoichiometric and catalytic reactions of chemically modest small molecules such as CH_4,CO and CO_2.
We have extended works to synthesize Rh_<6-x>Ir_x(CO)_<16>(x=0-6) and Rh_4Fe_2(CO)_<15>^<2-> inside NaY zeolite by the "ship-in-bottle" technique, and characterized the H_2-reduced bimetal ensembles by EXAFS, FTIR, and Mossbauer in CO and CH_4 atmosphere. NaY-entrapped RhIr ensembles provide selectively C_2H_6 via central C-C bond-scission in the butane hydrogenolysis, while NaY-entrapped RhFe ensembles selective towards CH_4+C_3H_8 via terminal C-C bond scission. Recently, we have succeeded to synthesize the series of Chini-type Pt clusters such as [Pt_3(CO)_6]_n^<2-> (n=3,4,5) inside NaY cages, which are characterized by FTIR, EXAFS and UV-vis. They are catalytically active for NO reaction with CO and the water gas shift reaction (CO+H_2O=CO_2+H_2) at lower temperatures, and exhibited effective photocatalysis for the latter reaction with a marked enhancement under the illumination of a Xe lamp compared with the dark reduction. The results suggest that H_2O is activated with anionic Pt carbonyl clusters inside the cages to promote the H (or OH) formation under the photo-illumination.
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