Open Access Research Article Issue
Selective liquid phase oxidation of cyclohexane over Pt/CeO2–ZrO2–SnO2/SiO2 catalysts with molecular oxygen
Journal of Advanced Ceramics 2015, 4 (2): 111-117
Published: 30 May 2015

Partial oxidation of cyclohexane into cyclohexanone and cyclohexanol (KA-oil) is an industrially significant reaction for producing precursors for the synthesis of ε-caprolactam and adipic acid, which are the building blocks of nylon. However, to date, the cyclohexane conversion ratio has usually been limited to less than 6% to prevent further oxidation of the cyclohexanol and cyclohexanone targets. In this study, we report that Pt/CeO2–ZrO2–SnO2/SiO2, in which CeO2–ZrO2–SnO2 provide reactive oxygen molecules from inside the bulk, can act as efficient catalysts. Optimization of the catalyst composition and reaction conditions provided a cyclohexane conversion ratio of 24.1% and a total selectivity for cyclohexanol and cyclohexanone of 83.4% at 130 ℃ in 0.5 MPa (4.9 atm) air for 7 h over a 5wt%Pt/16wt%Ce0.68Zr0.17Sn0.15O2.0/SiO2 catalyst. This catalyst has significant advantages over conventional catalysts because the reaction proceeds at a lower pressure, and there is no need for toxic radical initiators or free-radical scavengers.

Open Access Research Article Issue
Catalytic liquid phase oxidation of 1,4-dioxane over a Pt/CeO2–ZrO2–Bi2O3/SBA-16 catalyst
Journal of Advanced Ceramics 2015, 4 (1): 71-75
Published: 31 January 2015

A Pt/CeO2–ZrO2–Bi2O3/SBA-16 (Santa Barbara Amorphous No. 16) catalyst was prepared by hydrothermal and wet impregnation methods for catalytic purification of 1,4-dioxane in water. SBA-16 has a number of mesopores and the average size of the pores is 9.4 nm. In the present catalyst, platinum and CeO2–ZrO2–Bi2O3 were successfully dispersed in the pores of the SBA-16 support, and the temperature dependence of the liquid phase oxidation of 1,4-dioxane was examined. The oxidation reaction proceeded effectively in the air atmosphere in the temperature range of 40– 80 ℃.

Open Access Research Article Issue
Novel environmentally friendly inorganic red pigments based on calcium bismuth oxides
Journal of Advanced Ceramics 2015, 4 (1): 39-45
Published: 31 January 2015

Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide, Ca3(Bi1−xREx)8O15 (0 ≤ x ≤ 0.09; RE = Sc3+, Er3+, Y3+, Ho3+ and Dy3+), were successfully synthesized and the color properties were characterized. The color of these pigments depended on the composition and the synthesis condition, and the most vivid red color was obtained for the Ca3(Bi0.93Y0.07)8O15 sample calcined thrice at 800 ℃ for 2 h. The L* and a* values corresponding to brightness and red chromaticity for this pigment were 45.6 and +30.6, respectively, which were greater than those of a commercially available Fe2O3 pigment (L* = 38.4, a* = +29.5). Since the present pigment is composed of nontoxic and safe elements, it should be an attractive alternative to the conventional Fe2O3 pigment.

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