The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Hiromichi Arai - One of the best experts on this subject based on the ideXlab platform.

  • role of a and b cations in Catalytic Property of substituted hexaaluminate abal11o19 α for high temperature combustion
    Studies in Surface Science and Catalysis, 1996
    Co-Authors: Koichi Eguchi, Hiroshi Inoue, Koshi Sekizawa, Hiromichi Arai
    Abstract:

    Cation-substituted hexaaluminate compounds, ABAl 11 O 19−α , were investigated for application to high temperature Catalytic combustion. Two series of modifications of the compounds was made by cation substitution; substitution of large cations in the mirror plane with lanthanides ions, and substitution of transition metals for Al site in the spinel block. In a series of AMnAl 11 O 19−α (A=La, Pr, Sm and Nd), surface area and Catalytic activity increased with an increase in ionic radius of lanthanides. La 3+ is superior as the large cation in the mirror plane of the hexaaluminate to other tri-valent cations with small ionic radii. The Catalytic activities of LaBAl 11 O 19−α (B=Cr, Mn, Fe, Co, Ni, and Cu) were enhanced when Mn and Cu were employed as the B-site substituents. Althoug Mn and Cu were also effective substituents for enhancing Catalytic activity in Ba-based hexaaluminate compounds, their activity was low as compared with the La-based catalysts. These results indicate that the redox cycle of transition metal in hexaaluminate lattice and Catalytic activity appears to be affected sensitively with the electronic or structural effect of large cation in the mirror plane.

Lei Shen - One of the best experts on this subject based on the ideXlab platform.

Hengbo Yin - One of the best experts on this subject based on the ideXlab platform.

  • Preparation of mesoporous titania solid superacid and its Catalytic Property.
    Journal of Hazardous Materials, 2008
    Co-Authors: Tingshun Jiang, Qian Zhao, Hengbo Yin
    Abstract:

    Mesoporous titania (TiO(2)) was synthesized by hydrothermal method using cetyltrimethyl ammonium bromide (CTAB) as a template and using anhydrous ethanol and tetra-n-butyl titanate (TBOT) as raw materials. Mesoporous titania solid superacid and nanosized titania solid superacid catalysts were prepared by wet impregnation method. The structure and Property of as-prepared samples were characterized by means of XRD, FT-IR and N(2) physical adsorption. The esterification of salicylic acid with isoamyl alcohol and the condensation of cyclohexanone with ethylene were used as model reactions to test the Catalytic activities of the catalysts. On the other hand, the comparison of Catalytic activities of the prepared solid superacid catalysts and the conventional liquid acid H(2)SO(4) was also carried out under the same experimental conditions. The results show that the Catalytic activities of the prepared solid superacid catalysts were higher than that of the conventional liquid acid H(2)SO(4), and that the Catalytic activity of mesoporous TiO(2) solid superacid is the highest among the three catalysts. Mesoporous TiO(2) solid superacid is a good catalyst for the synthesis of isoamyl salicylate or cyclohexanone ethylene ketal.

Shuichi Kagawa - One of the best experts on this subject based on the ideXlab platform.

  • synthesis of lakmno perovskite type oxides and their Catalytic Property for simultaneous removal of nox and diesel soot particulates
    Applied Catalysis B-environmental, 2001
    Co-Authors: Yasutake Teraoka, Kazunori Kanada, Shuichi Kagawa
    Abstract:

    Abstract Mixed metal oxides in the LaKMnO system were synthesized and their Catalytic properties toward the simultaneous NO x –soot removal reaction were investigated. The solubility limit of K in La 1− x K x MnO 3 was determined between 0.2 and 0.25 from X-ray diffraction (XRD) measurement and crystal structure investigation, and K 2 Mn 4 O 8 was by-produced beyond the solubility limit. The activity and the NO x reduction selectivity depended significantly on the K content, and the oxides with intermediate K contents ( x =0.2 and x =0.25) or with the composition close to the solubility limit were good catalysts with higher activity and selectivity. The present study revealed that the LaKMnO oxides are good candidates of catalysts for the simultaneous NO x –soot removal reaction.

  • promotion effect of potassium on the Catalytic Property of cufe2o4 for the simultaneous removal of nox and diesel soot particulate
    Applied Catalysis B-environmental, 1998
    Co-Authors: Wenfeng Shangguan, Yasutake Teraoka, Shuichi Kagawa
    Abstract:

    Abstract Modification of CuFe2O4 catalyst for the simultaneous NOx-soot removal has been studied by doping alkali metals (Li, Na, K, Cs), vanadium and platinum. In pre-doped catalysts, designated as Cu1−xAxFe2O4 (A : dopant), potassium was superior to the other alkali metals and vanadium with respect to enhancing the activity and selectivity to NOx reduction into N2, and the optimum doping level of potassium was x=0.05. Such a promotion effect of potassium was also observed with the impregnated 5 mol% K/CuFe2O4 catalyst. The impregnation of platinum to CuFe2O4 and Cu0.95K0.05Fe2O4 resulted in a decrease in the selectivity to N2 formation with the activity being almost unchanged. The high Catalytic performance, especially high selectivity, was realized only when the proper amount of potassium is doped in the Cu–Fe spinel catalyst. XPS analysis showed the segregation (enrichment) of potassium on the surface, and too much doping of potassium might cause the covering of active sites of the Cu–Fe spinel oxide.

Dian Yu Chen - One of the best experts on this subject based on the ideXlab platform.

  • synthesis crystal structure and Catalytic Property of a new samarium compound derived from 5 pyrazin 2 yl tetrazole 2 acetic acid
    RSC Advances, 2015
    Co-Authors: Dian Yu Chen, Qiao Yun Li, Gao Wen Yang, Jie Yang, Lei Shen
    Abstract:

    [Sm(pztza)2(H2O)6]·pztza·3H2O has been prepared by the reaction of SmCl3·6H2O and 5-(pyrazin-2-yl)tetrazole-2-acetic acid (Hpztza) under the presence of potassium hydroxide. The compound has been structurally characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The X-ray analysis demonstrates this complex displays a mononuclear structure. Furthermore, it shows an excellent Catalytic Property for polymerization of vinyl monomers and the polymerization shows controlled characteristics. It can be isolated from the reaction system and reused at least 10 times.

  • synthesis crystal structure and Catalytic Property of a samarium complex with hpytza hpytza 5 3 pyridyl tetrazole 2 acetic acid
    Inorganic Chemistry Communications, 2014
    Co-Authors: Dian Yu Chen, Wu Xiang Li, Qiao Yun Li, Gao Wen Yang, Ya Mei Ding, Bo Xu, Juan Wang, Ying Zhang, Xiao-feng Shen
    Abstract:

    Abstract A reaction of SmCl 3 ·6H 2 O and Hpytza (Hpytza = 5-(3-pyridyl) tetrazole-2-acetic acid) under the presence of KOH, produced a novel coordination compound, [Sm(pytza) 2 Cl(H 2 O) 2 ] ( 1 ). This compound was structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compound 1 reveals an 1D structure via its bridging pytza ligand and simultaneously shows a specific and good Catalytic behavior for the photo-polymerization of vinyl monomers. Furthermore, the high molecular weight polymers with narrow polydispersity were obtained, and the polymerization showed controlled characteristics. The catalyst can be isolated from polymer products easily and reused for at least 10 times.