Shu‐ichi Niwa

National Institute of Advanced Industrial Science and Technology

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Fujio Mizukami

National Institute of Advanced Industrial Science and Technology

Makoto Toba

National Institute of Advanced Industrial Science and Technology

Yoshimichi Kiyozumi

National Institute of Advanced Industrial Science and Technology

Kazuyuki Maeda

Tokyo University of Agriculture and Technology

Yoshio ORITO

National Chemical Laboratory

Sumi IMAI

Nitto Chemical Industry (Japan)

Juichi IMAMURA

Sumitomo Metal Mining (Japan)

Kazuo Shimizu

Shizuoka University

Tohru Tsuchiya

Toyohashi University of Technology

Imre Kiricsi

University of Szeged

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National Institute of Advanced Industrial Science and Technology

National Institute for Materials Science

National Chemical Laboratory

Nitto Chemical Industry (Japan)

The University of Tokyo

National Institute of Materials Physics

University of Szeged

Industrial Research Institute

Malaysian Palm Oil Board

Institute of Materials and Environmental Chemistry

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Oxygenation of cyclohexylbenzene catalyzed with hydrogen bromide.

NIPPON KAGAKU KAISHI (1988)

Tohru Tsuchiya Pongchan Chandayot Fujio Mizukami Kazuo Shimizu Shu‐ichi Niwa

シクロヘキシルベンゼン(CHB)の酸素酸化/酸分解反応を無触媒および臭化水素触媒存在下で検討した。無触媒時の自動酸化では,生成物の1-フェニルシクロヘキシルヒドロペルオキシド(PCP)の選択率は,温度あるいは酸素圧にかかわりなく,もっぱら原料転化率によって決まり,実際的な反応温度範囲の90～140℃では,CHB転化率40%でPCP選択率80%であった。クメンの自動酸化では考慮する必要のなかった,第二級炭素上からの水素の引き抜きもCHBでは無視できない。臭化水素存在下では,反応は常圧下室温以下で酸素供給律速で進みフェノールとシクロヘキサノンが主生成物であった。フェノールを産出する特異な酸素酸化であるが,ベンゼンジオールによって完全に阻害されるなどの特徴から,この反応がラジカル過程で進むことが明らかになった。臭化水素は反応開始剤およびBrラジカルの供給源となり,このBrラジカルがCHBからの水素引き抜き剤として働くため,反応は無触媒時にくらぺ圧倒的に速く進むと考えられる。CHB転化率は仕込みHBr量に依存し,-8℃ から30℃ではO2/HBr=3.2の比率で酸素が吸収された。ところがHBr濃度が一定値を超えると反応が阻害される臨界現象が現われた。トリフルオロ酢酸をHBrとともに用いることにより,臨界現象はもっぱら酸濃度に依存することが明らかになり,生成物から副生する阻害剤に起因すると推定された。HBrはCHBの酸素酸化にきわめて有効な触媒であると結論された。

Hydrogen bromide

10.1246/nikkashi.1988.17

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Citations (1)

Uniform distribution of copper and cobalt during the synthesis of SiMFI-5 from kanemite through solid-state transformationElectronic supplementary information (ESI) available: XRD patterns for CoSiMFI and CuSiMFI samples synthesised by SST at various stages in the process and containing different metal loadings. See http://www.rsc.org/suppdata/jm/b2/b207539n/

Journal of Materials Chemistry (2003)

Stefan Marcel Ciocîlteu M. Salou Yoshimichi Kiyozumi Shu‐ichi Niwa Fujio Mizukami

Two types of Cu- and Co-containing SiMFI samples were prepared through solid-state transformation (SST) from kanemite by adding metal nitrate directly to the synthesis mixture and by impregnation. Samples were characterized using XRD, ICP, TEM and TPR. XRD and TEM data show that both metals are highly dispersed inside the bulk zeolites for the SST samples. For samples containing more than 10 wt% cobalt, the characteristic metal oxide peaks were observed after calcination. In the case of CuSiMFI, narrow metal peaks are observed by XRD after reduction. The particle sizes are in the range 2–6 nm for the samples prepared by SST and exhibit a broad distribution range for those synthesized by the impregnation method. XRD shows that the samples have the SiMFI structure, independent of metal content. Despite the high metal content, the CoSiMFI and CuSiMFI samples prepared by SST show a high level of metal dispersion in the zeolite bulk.

10.1039/b207539n

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Partial hydrogenation of benzene with ruthenium catalysts prepared by a chemical mixing-spray drying procedure.

NIPPON KAGAKU KAISHI (1990)

Shu‐ichi Niwa Fujio Mizukami Makoto TUBA Tatuo MURAKAMI Masami Ueda

高牲能で,かつ安価なシクロヘキセン合成用触媒の開発を目的に化学混合法と噴霧乾燥法を利用する触媒調製法とそれを用いる反応条件を検討した。触媒担体原料として市販の9種類のコロイドゾルを用いて触媒を調製した結果.スノーテックス-C(シリカ)を担体原料とし.エチレングリコールに塩化ルテニウム(III)を溶解した溶液を加え均一分散溶液としこれを噴霧轍した触媒ゲルを.さらに6l/h,の水素流通下で400℃,1～5時間,活性化処理した触媒がベンゼンからのシクロヘキセン合成に最も,好適であった。なお,触媒調製時に用いるエチレングリコール量はシリカに対してモル比で2.5～3.8倍がよかった。上記の条件で調製された1wt%Ru-0.1 wt% Cu-SiO2触媒2gをベンゼン160m1および水100mlの混合液に加え,反応温度180℃,水素圧70kg/cm2で,硫酸コバルト(II)のようなr腐食性添加物を併用することなく反応を行ったところ,34.7%の収率でシクロヘキセンが生成した。ヲノヘゴリさらに,この反応系中に非腐食性の1.4-ブタンジオールあるいはベンジルアルコールを少量添加するとシクロヘキセン収率は約40%となった。この最高収率を得た条件下で反応をくり返し,触媒寿命を調べた。反応回数の増加にしたがいシクロヘキセン収率の低下が認められたが,触媒を最初の活性化条件で再び処理すると,触媒は初期活性をほぼ完全に回復した。この実験では,触媒は3回の再生処理を施すことにより35回くり返し使用され,この間シクロヘキセン収率は25～40%であった。

10.1246/nikkashi.1990.284

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Direct hydroxylation of aromatic compounds by a palladium membrane reactor

Catalysis Today (2005)

Koichi Sato Takaaki Hanaoka Shu‐ichi Niwa Ciocilteu Stefan Takemi Namba

Hydroxylation

Membrane reactor

10.1016/j.cattod.2005.03.067

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Citations (58)

Synthesis of cordierite by complexing agent-assisted sol–gel procedure

Journal of the Chemical Society Chemical Communications (1990)

Kazuyuki Maeda Fujio Mizukami Setsuo Miyashita Shu‐ichi Niwa Makoto Toba

K. Maeda, F. Mizukami, S. Miyashita, S. Niwa and M. Toba, J. Chem. Soc., Chem. Commun., 1990, 1268 DOI: 10.1039/C39900001268

Cordierite

Diethylene glycol

10.1039/c39900001268

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Effect of preparation methods on properties of alumina/titanias

Journal of Materials Chemistry (1994)

Makoto Toba Fujio Mizukami Shu‐ichi Niwa Yoshimichi Kiyozumi Kazuyuki Maeda

Alumina/titanias have been prepared by three methods: complexing-agent-assisted sol–gel; coprecipitation; and hydrogel kneading. The relationship between the preparation methods and the properties of the alumina/titanias was investigated by thermal gravimetry and differential thermal analysis (TG–DTA), X-ray powder diffraction, laser Raman spectroscopy, solid-state magic-angle spinning nuclear magnetic resonance (MAS-NMR), ammonia temperature-programmed desorption (TPD) and nitrogen adsorption. Of the three preparation methods, the complexing-agent-assisted sol–gel method gave the most homogeneous alumina/titanias, and their acidities and specific surface areas depended on complexing agents used in the preparation and the Ti:Al ratios of the raw materials. In contrast, kneading alumina/titanias were relatively heterogeneous and their properties did not depend on the Ti:Al ratio. Regarding the dependences of properties of alumina/titanias on the Ti:Al ratio, coprecipitation alumina/titanias are intermediate between complexing-agent-assisted sol–gel and kneading ones.

Coprecipitation

Magic angle spinning

Differential thermal analysis

10.1039/jm9940400585

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Preparation of Mesoporous Composite Materials by Pillaring of Magadiite with Silica

Molecular crystals and liquid crystals science technology. Section A, Molecular crystals and liquid crystals/Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals (1998)

Á. Fudala Yoshimichi Kiyozumi Fujio Mizukami Makoto Toba Shu‐ichi Niwa

Abstract Succesful attempt was made to intercalate silicate between the layers of sheet silicate magadiite. Both the interlayer distance and the BET value increased as the result of layers propped apart. SEM images evidence structure changes occured.

10.1080/10587259808042405

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Selective hydrogenation of oleic acid to 9‐octadecen‐1‐ol: Catalyst preparation and optimum reaction conditions

Journal of the American Oil Chemists Society (1992)

Kien Yoo Cheah T. S. Tang Fujio Mizukami Shu‐ichi Niwa Makoto Toba

A new catalyst, ruthenium‐tin‐alumina is found to selectively hydrogenate oleic acid to 9‐octadecen‐1‐ol (oleyl + elaidyl alcohol) at low pressure with high yield. Catalyst preparation methods, catalyst raw materials and activation conditions have a significant effect on the activity of the catalyst. The optimum atomic ratio of ruthenium to tin is about 1:2. Catalyst prepared by an improved sol‐gel method shows higher activity and selectivity than catalysts prepared by impregnation and coprecipitation methods. Chloride is found to have a negative effect on catalytic activity. The best catalyst is prepared from chloride‐free ruthenium and tin raw materials. Under the optimum reaction conditions of 250°C and 5.6 MPa, the selectivities for 9‐octadecen‐1‐ol and total alcohol (9‐octadecen‐1‐ol + stearyl alcohol) formation are 80.9% and 97%, respectively, at a conversion of 81.3%.

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Oleyl alcohol

10.1007/bf02540940

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Hydrogenation of ethyl phenylacetate to 2-phenylethanol by ruthenium/tin/alumina catalysts elimination of need for high temperature activation of the catalysts with hydrogen; optimum oxidation state of tin

Applied Catalysis A General (1997)

Ryuji Kikuchi Fujio Mizukami Shu‐ichi Niwa Makoto Toba Hirobumi Ushijima

Phenylacetate

10.1016/s0926-860x(97)00211-1

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Citations (7)