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Durch Zugabe von CsNO3‐ bzw. KNO3‐Lösungen zu RuC13/ Al2O3 und anschließende Reduktion mit H, werden Alkalimetallhydroxid‐verstärkte Ru/Al2O3‐Katalysatoren hergestellt und mit XPS, TPR (temperature‐programmed reduction), DTG und DTA untersucht.

Magnon propagation length in a ferrimagnetic insulator yttrium iron garnet (YIG) has been investigated by measuring and analyzing the YIG-thickness tYIG dependence of the spin Peltier effect (SPE) in a Pt/YIG junction system. By means of the lock-in thermography technique, we measured the spatial distribution of the SPE-induced temperature modulation in the Pt/YIG system with the tYIG gradation, allowing us to obtain the accurate tYIG dependence of SPE with high tYIG resolution. Based on the tYIG dependence of SPE, we verified the applicability of several phenomenological models to estimate the magnon diffusion length in YIG.

One-pot amination of fatty alcohols with dimethylamine at normal pressure, using Cu/Ni-based colloidal catalyst stabilized by barium sterate (Cu/Ni/Ba colloidal catalyst, Cu:Ni:B = 5:1:1). proceeded without charging bulk hydrogen with an amine yield of more than 90%. It demonstrated the effective use of active hydrogen, generated by the dehydrogenation of a starting alcohol over copper, for the following hydrogenolysis of an aldehyde-dimethylamine adduct to form the final product, N,N-dimethil-long alkyltertiary amines. The basic function generated by the combination of copper and nickel, especially in a colloidal state, was named as ''Self-supplying System for Active Hydrogen''. On the other hand, reductive amination of aldehydes with dimethylamine, in the presence of hydrogen flow at a normal pressure using the same colloidal catalyst, proceeded with an amine yield of 40-80%, and significant amount (12-26%) of aldols were formed. These observations demonstrated the essential difference between one-pot amination of alcohols containing active hydrogen and reductive amination of aldehydes in the presence of bulk hydrogen which has to be activated separately. This is the first description of basic function of Cu/Ni-based catalyst by the original inventors of the catalytic system. More than five-fold increase in catalytic activity by incorporation of calcium stearate with Cu/Ni was observed for one-pot amination of fatty alcohols. Comparison of catalytic activity of Cu/Ni-based catalyst in a colloidal state and in a solid state showed superiority of the former catalyst in catalytic activity, 40-50 times higher based on a unit amount of copper.

Fatty alcohols are obtained by hydrogenation of fatty acid methyl esters derived from coconut oil and palm kernel oil. Cu-Cr has been widely used as a hydrogenation catalyst. We have developed a new environment-friendly catalyst that could substitute for the conventional Cu-Cr catalyst, preventing the release of toxic hexavalent Cr. Here we report the development of Cr-free, Cu-Fe-Al oxide catalyst. We found that iron has a strong promoting effect nearly equivalent to that of Cr and that the addition of Al significantly improved the reuse property (durability) through a study of trivalent metal addition to Cu. Powder X-ray diffraction analysis of the used catalyst revealed that the Al addition suppressed the transformation of the CuFe 2 O 4 component (Cu-Fe spinel) to α-Fe. It was concluded that the stabilization of CuFe 2 O 4 during reduction improved the catalyst durability. A plant-scale experiment confirmed that the Cu-Fe-Al oxide catalyst performs as well as the conventional Cu-Cr catalyst.Paper no. J9579 in JAOCS 77, 1283 -1287 (December 2000. KEY WORDS:Cu-Cr, Cu-Fe-Al oxide catalyst, fatty acid methyl ester, fatty alcohol, non-Cr hydrogenation catalyst, slurry-bed process, spinel.Fatty alcohols are mainly derived from vegetable oils such as palm kernel oil and coconut oil and serve as raw materials for various household products and surfactants. Fatty alcohols are produced by continuous hydrogenation of fatty acids or fatty acid methyl esters under high temperature (250-300°C) and high hydrogen pressure (25-35 MPa) in a liquid-phase slurry-bed process. The catalyst used in this process consists mainly of copper-chromite (Cu-Cr) oxide as a basic structure (1-3). Although many modifications have been made for practical use, basic composition has not changed from the original. Safety is a major concern in using Cu-Cr catalyst since hexavalent Cr is discharged in catalyst manufacturing. Fatty alcohol producers and catalyst manufacturers have attempted to develop non-Cr catalysts for many years; however, non-Cr catalysts with equivalent performance to the Cu-Cr catalyst have not been developed to date. Catalysts must have high activity, selectivity, and durability (catalyst life). A catalyst used in a slurry-bed system should have filtration, sedimentation, and agglomeration properties for stable operation.We have developed an environment-friendly Cu-based Crfree catalyst, and the results are presented here. EXPERIMENTAL PROCEDURESFatty acid methyl ester was used as raw material for the hydrogenation reaction. It was obtained by transesterification of coconut oil or palm kernel oil with methanol. Transesterification was carried out at 80°C for 3 h with 0.5 wt% of NaOH as a catalyst. Methyl ester was washed and dried before reaction to remove glycerin formed as a by-product.Cu-metal oxide catalysts were prepared by a coprecipitation method. Aqueous solutions of Cu sulfate (Meltex Inc., Tokyo, Japan) and various metal sulfates were stirred at 90°C, and 22% Na 2 CO 3 solutions were added to pH 9.0 and kept for 1 ...