Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yt...Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yttrium sites with terbium in a (Y0.97Zr0.03)2O3.03 catalyst, which shows high NO decomposition activity. Among the catalysts synthesized in this study, the (Y0.67Tb0.30Zr0.03)2O3.33 catalyst exhibited the highest NO decomposition activity;NO conversion to N2 was as high as 67% at 900℃ in the absence of O2 (NO/He atmosphere), and a relatively high conversion ratio was observed even in the presence of O2 or CO2, compared with those obtained over conventional direct NO decomposition catalysts. These results indicate that the C-type cubic Y2O3–Tb4O7–ZrO2 catalyst is a new potential candidate for direct NO decomposition.展开更多
Partial oxidation of cyclohexane into cyclohexanone and cyclohexanol(KA-oil)is an industrially significant reaction for producing precursors for the synthesis ofε-caprolactam and adipic acid,which are the building bl...Partial oxidation of cyclohexane into cyclohexanone and cyclohexanol(KA-oil)is an industrially significant reaction for producing precursors for the synthesis ofε-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/CeO_(2)-ZrO_(2)-SnO_(2)/SiO_(2),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%Ce_(0.68)Zr_(0.17)Sn_(0.15)O_(2.0)/SiO_(2)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.展开更多
A Pt/CeO_(2)-ZrO_(2)-Bi_(2)O_(3)/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 mesopo...A Pt/CeO_(2)-ZrO_(2)-Bi_(2)O_(3)/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 CeO_(2)-ZrO_(2)-Bi_(2)O_(3)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℃.展开更多
Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide Ca3(Bi1-xREx)8O15(0≤x≤0.09;RE=Sc^(3+),Er^(3+),Y^(3+),Ho^(3+)and Dy^(3+)),were successfully synthesized and the color properties we...Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide Ca3(Bi1-xREx)8O15(0≤x≤0.09;RE=Sc^(3+),Er^(3+),Y^(3+),Ho^(3+)and Dy^(3+)),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.展开更多
Pt/CeO2–ZrO2–SnO2/γ-Al2O3 catalysts were prepared by co-precipitation and wet impregnation methods for catalytic oxidation of acetaldehyde to acetic acid in water. In the present catalysts, Pt and CeO2–ZrO2–SnO2 ...Pt/CeO2–ZrO2–SnO2/γ-Al2O3 catalysts were prepared by co-precipitation and wet impregnation methods for catalytic oxidation of acetaldehyde to acetic acid in water. In the present catalysts, Pt and CeO2–ZrO2–SnO2 were successfully dispersed on the γ-Al2O3 support.Dependences of platinum content and reaction time on the selective oxidation of acetaldehyde to acetic acid were investigated to optimize the reaction conditions for obtaining both high acetaldehyde conversion and highest selectivity to acetic acid. Among the catalysts, a Pt（6.4 wt.%）/Ce0.68Zr0.17Sn0.15O2.0（16 wt.%）/γ-Al2O3 catalyst showed the highest acetaldehyde oxidation activity. On this catalyst, acetaldehyde was completely oxidized after the reaction at 0°C for 8 hr, and the selectivity to acetic acid reached to 95%and higher after the reaction for 4 hr and longer.展开更多
The research trend in rare earths has been studied using the Chemical Abstracts (CA) data. The number of papers published from China has been increasing very rapidly since 2001 and today China is the top country in te...The research trend in rare earths has been studied using the Chemical Abstracts (CA) data. The number of papers published from China has been increasing very rapidly since 2001 and today China is the top country in terms of paper contribution on rare earths. This article presents a comparative study of R&D trends among China, Japan and USA.展开更多
文摘Catalytic activities for direct NO decomposition were investigated over C-type cubic Y2O3–Tb4O7–ZrO2 prepared by a coprecipitation method. The NO decomposition activity was enhanced by partial substitution of the yttrium sites with terbium in a (Y0.97Zr0.03)2O3.03 catalyst, which shows high NO decomposition activity. Among the catalysts synthesized in this study, the (Y0.67Tb0.30Zr0.03)2O3.33 catalyst exhibited the highest NO decomposition activity;NO conversion to N2 was as high as 67% at 900℃ in the absence of O2 (NO/He atmosphere), and a relatively high conversion ratio was observed even in the presence of O2 or CO2, compared with those obtained over conventional direct NO decomposition catalysts. These results indicate that the C-type cubic Y2O3–Tb4O7–ZrO2 catalyst is a new potential candidate for direct NO decomposition.
文摘Partial oxidation of cyclohexane into cyclohexanone and cyclohexanol(KA-oil)is an industrially significant reaction for producing precursors for the synthesis ofε-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/CeO_(2)-ZrO_(2)-SnO_(2)/SiO_(2),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%Ce_(0.68)Zr_(0.17)Sn_(0.15)O_(2.0)/SiO_(2)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.
文摘A Pt/CeO_(2)-ZrO_(2)-Bi_(2)O_(3)/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 CeO_(2)-ZrO_(2)-Bi_(2)O_(3)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℃.
基金supported by the Development of Alternative Technology for Hazardous Chemical SubstancesDevelopment of Novel Environment-and Human-friendly Inorganic Pigments for Three Primary Colors(FY2010-2014)programs of the New Energy+1 种基金Industrial Technology Development Organization(NEDO)the Ministry of Economy,Trade and Industry,Japan(METI).
文摘Novel environmentally friendly inorganic red pigments based on calcium bismuth oxide Ca3(Bi1-xREx)8O15(0≤x≤0.09;RE=Sc^(3+),Er^(3+),Y^(3+),Ho^(3+)and Dy^(3+)),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.
文摘Pt/CeO2–ZrO2–SnO2/γ-Al2O3 catalysts were prepared by co-precipitation and wet impregnation methods for catalytic oxidation of acetaldehyde to acetic acid in water. In the present catalysts, Pt and CeO2–ZrO2–SnO2 were successfully dispersed on the γ-Al2O3 support.Dependences of platinum content and reaction time on the selective oxidation of acetaldehyde to acetic acid were investigated to optimize the reaction conditions for obtaining both high acetaldehyde conversion and highest selectivity to acetic acid. Among the catalysts, a Pt（6.4 wt.%）/Ce0.68Zr0.17Sn0.15O2.0（16 wt.%）/γ-Al2O3 catalyst showed the highest acetaldehyde oxidation activity. On this catalyst, acetaldehyde was completely oxidized after the reaction at 0°C for 8 hr, and the selectivity to acetic acid reached to 95%and higher after the reaction for 4 hr and longer.
文摘The research trend in rare earths has been studied using the Chemical Abstracts (CA) data. The number of papers published from China has been increasing very rapidly since 2001 and today China is the top country in terms of paper contribution on rare earths. This article presents a comparative study of R&D trends among China, Japan and USA.
