1990 Fiscal Year Final Research Report Summary
Molecular Design of Cluster Catalysts in Micropore and Selective Activation of Alkanes
| Project/Area Number |
62470069
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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 |
工業物理化学
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| Research Institution | Hokkaido University |
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Principal Investigator |
ICHIKAWA Masaru Catalysis Research Center, Hokkaido University, Professor, 解媒化学研究センター, 教授 (70176288)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUOKA Atsushi Catalysis Research Center, Hokkaido University, Research Associate, 助手 (80189927)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Cluster / Zeolite / Alkane Activation / Bimetal Catalysts / Multisite Effect / Ensemble Effect / Ligand Effect / Hydrogenolysis |
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| Research Abstract |
A series of metal/bimetal catalysts have been prepared from the carbonyl clusters such as Rh_<6-X>Ir_X(CO)_<16> (X=0-6) and [Fe_2Rh_4(CO)_<16>]^<2-> which were synthesized inside NaY zeolite supercages. NaY-entrapped Rh_6, Ir_6, Rh_4Ir_2, Rh_3Ir_3, and Rh_2Ir_4 crystallites derived from the carbonyl clusters have been well characterized by FTIR, ^<129>Xe NMR, and CO/H chemisorption on their metallic structure and electronic states. The results suggested that the reduced crystallites inside NaY zeolite consisted of the cluster ensemble with the controlled metal compositions and fairly stabilized through several sequence of oxidation, reduction, and alkane hydrogenolysis. As the test reactions, hydrogenlysis of n-butane and ethane, and benzene hydrogenation were conducted. It is of interest to observe the dramatic decrease of hydrogenolysis activity by four order of magnitude across the series of clusters by increasing the number of modest Ir atoms in the active Rh ensembles, while a slight enhanacement activity for the benzene hydrogenation. For butane hydrogenolysis, the smaller Rh ensembles in the bimetallic clusters gave the maximum selectivities towards the central C-C bond scission to give C_2H_6.
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