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Reconstructed layered double hydroxides (LDHs), which are obtainable from stirring in water after heat treatment at the high temperature, function as solid base catalysts in water. Aldol self-condensation of acetone is often used to investigate the base property of catalysts. In this study, we evaluated the base property of Mg-Al, Mg-Ga, and Mg-In LDHs using the self-aldol condensation of acetone. It is found that the constituent elements of LDHs contribute to the basicity.

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Copper-diphosphine complexes are found to be highly active and selective homogeneous catalysts for hydrosilylation of CO₂. The structure of the phosphine ligands strongly affects catalytic activity. Turnover number reaches 70000 after 24 h with 1,2-bis(diisopropylphosphino)benzene as a ligand under 1 atm CO₂. ¹H, ¹³C, ³¹P, ¹H-³¹P HSQC, and ¹³C-¹H HETCOR NMR spectra under reaction conditions showed the reaction mechanism through insertion of CO₂ to Cu-H to afford Cu-formate.

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The rebound hardness tests have been used commonly as a technique for hardness measurements. The effect on the hammer motion of lubricant existing on the specimen surface is studied.  It is found that in the case of the hammer with spherical indenter, deeper indentation is formed on the lubricated surface than that on the dry surface.  And the difference of coefficient of restitution between dry and lubricated surfaces increases with decreasing the impacting speed.  On the other hand, in the case of the hammer with sharp indenter and with high rigidity body, the coefficient of restitution keeps almost the constant value irrespective of the lubricant and the impact speed.

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We have reported that hydrogen evolution is observed as a result of decomposition of hydrocarbon oil during lubrication. Mechanical properties of materials should be altered by the effect of hydrogen. In this paper, we will focus on the chemical activity of nascent steel surface formed by mechanical contact under severe conditions. Effects of lubricating conditions and additives on tribochemical hydrogen evolution will be discussed from the viewpoint of surface chemistry.

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Component and structure of lubricant films under elasto-hydrodynamic lubirication(EHL) are altered by the effects of high pressure and shearing at Hertzian contacts resulting in change of viscosity which affects lubricating properties of the lubricants. In this paper, the molecular interaction between lubricant components(base oil and additive) has been investigated by in situ observation with a micro-FTIR.

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The concentrations of additives in the lubricant films at sliding contacts were measured by in-situ observation using micro-Fourier transform infraed spectroscopy. The change in concentration was dependent on sliding speed and additive itself. The concentration of dispersant increased but that of FM decreased at higher sliding speed. A new friction mechanism for wet clutches was proposed on the basis of viscosity change due to additive concentration at sliding contacts.

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Boundary lubrication characteristics are closely dependent on chemical structure of boundary lubricating films which are formed tribochemical reaction at lubricating contacts. TOF-SIMS has an excellent power for chemical analysis with high chemical and spatial resolution. In this paper, recent results obtained by TOF-SIMS analysis of boundary films will be presented.

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12CaO·7Al₂O₃ electride (C12A7:e^-)with alow work function was synthesized under a reducing atmosphere by utilizing a stable inorganic oxide, 12CaO·7Al₂O₃ which is a commercial alumina cement with a mayenite structure. Ru-loaded C12A7:e^- exhibited a remarkable catalytic activity for ammonia synthesis and the activation energy was about one-half of that of conventional catalysts. Such high catalytic performance of Ru/C12A7:e^- is attributed to efficient electron donation from C12A7:e^- to antibonding orbitals of N₂ through Ru nanoparticle.

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Catalysis of a vanadium compound prepared from V₂O₅, D,L-tartaric acid was study for oxidation. It was found that the vanadium compound showed hydroxylation catalysis of benzene with H₂O₂.

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Precise syntehsis of polyolefin containing reactive functinality has been achieved in the ethylene/alfa-olefin copolymerization using half-titanocene in the presence of p-methylstyrene or bivinylbiphenyl.  The resultant polymer possessed high molecular weight with uniform compositions, and the contents could be varied by modification of monomer concentration charged.  Further functionalization has also been achieved from the resultant coolymers.

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Copolymerization of ethylene with cyclic olefins such as norbornene, substituted cyclohexenes have been explored in the presence of half-titanocene catalysts.  In particular, the aryloxo-modified catalysts exhibited moderate substituted cyclohexene incorporation in the copolymerization for the first time.

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Synthesis of variosu titanatranes, [(OArCH₂)₃N]Ti(X), and their use as ethylene polymerizatin catalysts have been explored.  These complexes exhibited high catalytic activities in the presence of MAO especially at high temperature.  Effect of AlMe₃ including isolation of hetero-bimetallic Ti-Al complexes will be introduced in the symposium.

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The use of SiO₂-supported MAO is the simplest supporting method of single-site catalysts. In this paper, we conducted olefin polymerization with a Ni-based and a Ti-based catalyst activated by several SiO₂-supported MAO and evaluated the homogeneity of the SiO₂-supported MAOs based on the primary structure of the polymers obtained.

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Methylaluminoxane has been widely used as an cocatalyst for homogeneous polymerization in the industrial fields. But there are not any reports on the precious structure of methylaluminoxane. We have been developing methylaluminoxane to improve the performance and clarify the structure of methylaluminoxane as the only producer in Japan. I would like to presentate some recent research topics together with our results in this presentation.

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Recently we have developed a coadsorption model for the high-precision description of active-site and surface structures of heterogeneous Ziegler-Natta catalysts.  We will present our ongoing research for the first ab-initio design of the catalysts, where structure-performance relationships for donors were examined using a modified coadsorption model. 

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