Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal tempera...Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.展开更多
Mesoporous Ce0.5Zr0.5O2 mixed oxide with high specific surface area was synthesized under basic condition in the presence of non-ionic surfactant PEG-4000. The effect of synthesis conditions, such as synthesis tempera...Mesoporous Ce0.5Zr0.5O2 mixed oxide with high specific surface area was synthesized under basic condition in the presence of non-ionic surfactant PEG-4000. The effect of synthesis conditions, such as synthesis temperature and the molar ratio of PEG-4000/（[ Ce] ＋ [ Zr] ）, on specific surface area were investigated. The products were characterized by transmission electron microscopy, powder X-ray diffraction, and nitrogen adsorption-desorption measurements, respectively. The results showed that synthesis temperature and the molar ratio of PEG-4000/（[ Ce] ＋ [ Zr] ） had great influence on specific surface area. Under the optimum synthesis conditions, the prepared Ce0.5Zr0.5O2 mixed oxide presented cubic fluorite-type structure and possessed high surface area of 148.6 m2·g^-1 with wormlike pores.展开更多
Mixture formed from sonicating TiCl4 and Si(OEt)4 in the absence of water is used as precursor and hydrolyzed by using a long-chain organic ammonium bromide as a structure-directing agent. The product, titania-silica,...Mixture formed from sonicating TiCl4 and Si(OEt)4 in the absence of water is used as precursor and hydrolyzed by using a long-chain organic ammonium bromide as a structure-directing agent. The product, titania-silica, is of mesoporous structure and characterized with SEM, FT-IR, BET, XRD and so on.展开更多
A novel sol-gel process for preparing oxides and mixed oxides sols from precipitation and peptization process is reported in this article. Inorganic salts are used as raw materials in this study. It is found that the ...A novel sol-gel process for preparing oxides and mixed oxides sols from precipitation and peptization process is reported in this article. Inorganic salts are used as raw materials in this study. It is found that the amount of acid has great influence on the stability and particle diameter distribution of the precursor sols. Ultrasonic treatment is used to prepare alumina sol at room temperature. The result of27Al NMR shows that there exist Al13 7+ species in the sol. By controlling the sol particles with narrow particle diameter distribution, alumina, titania and silica-alumina (SA) materials with narrow mesoporous distribution are formed by regular packing of sol particles during gelation without using any templates. The results also show that the structure and particle diameter distribution of precursor sol determine the final materials’ texture.展开更多
Mesoporous （MSU） Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of th...Mesoporous （MSU） Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of the pH value on the formation of mesostructure and the thermal stability of the material has been evaluated. The products were characterized by transmission electron microscopy, powder X-ray diffraction and nitrogen adsorption-desorption measurements. The results showed that the as-prepared Ce0.5Zr0.5O2 mixed oxide possessed a specific surface area of 163.3 m^2·g^-1, which had a cubic fluorite-type structure and possessed specific surface areas of 148.4 and 62.4 m^2·g^-1 after calcination at 500 and 800 ℃ for 2 h, respectively. The material showed excellent thermal stability.展开更多
Platinated W/Zr mixed oxides supported on mesoporous silica with various amounts of Si/Zr, namely PtWO_3/ZrO_2（[76_TD$IF]x）-HMS, were prepared and studied for n-heptane isomerization reaction at 200–350 C. The vari...Platinated W/Zr mixed oxides supported on mesoporous silica with various amounts of Si/Zr, namely PtWO_3/ZrO_2（[76_TD$IF]x）-HMS, were prepared and studied for n-heptane isomerization reaction at 200–350 C. The various methods such as XRD, XRF, FT-IR, UV–vis DRS, NH_3-TPD, H_2 chemisorption, nitrogen adsorption–desorption, Py-IR, SEM and TGA techniques were used for characterization of these materials. Kinetics of n-heptane isomerization was also investigated under various hydrogen. n-Heptane pressures and the influence of reaction conditions on catalytic performance were studied. The ideal catalytic performance was observed on HMS with 0.6%Pt/12%WO_3/ZrO_2 and Si/Zr = 10.展开更多
基金Project(CHCL0501) supported by Hubei Provincial Open Fund of Key Laboratory of Catalytic Material Science and Technology
文摘Mesoporous cerium-zirconium mixed oxides were prepared by hydrothermal method using cetyl trimethyl ammonium bromide (CTAB) as template. The effects of amount of template, pH value of solution and hydrothermal temperature on mesostructure of samples were systematically investigated. The final products were characterized by XRD, TEM, FT-IR, and BET. The results indicate that all the cerium-zirconium mixed oxides present a meso-structure. At molar ratio of n(CTAB)/n((Ce)+(Zr))= 0.15, pH value of 9, and hydrothermal temperature of 120 ℃, the samples obtained possess a specific surface area of 207.9 m2/g with pore diameter of 3.70 nm and pore volume of 0.19 cm3/g.
基金Project Supported by Open Fund of Key Laboratory of Catalysis Materials and Science of Hubei Province (CHCL0501)
文摘Mesoporous Ce0.5Zr0.5O2 mixed oxide with high specific surface area was synthesized under basic condition in the presence of non-ionic surfactant PEG-4000. The effect of synthesis conditions, such as synthesis temperature and the molar ratio of PEG-4000/（[ Ce] ＋ [ Zr] ）, on specific surface area were investigated. The products were characterized by transmission electron microscopy, powder X-ray diffraction, and nitrogen adsorption-desorption measurements, respectively. The results showed that synthesis temperature and the molar ratio of PEG-4000/（[ Ce] ＋ [ Zr] ） had great influence on specific surface area. Under the optimum synthesis conditions, the prepared Ce0.5Zr0.5O2 mixed oxide presented cubic fluorite-type structure and possessed high surface area of 148.6 m2·g^-1 with wormlike pores.
文摘Mixture formed from sonicating TiCl4 and Si(OEt)4 in the absence of water is used as precursor and hydrolyzed by using a long-chain organic ammonium bromide as a structure-directing agent. The product, titania-silica, is of mesoporous structure and characterized with SEM, FT-IR, BET, XRD and so on.
基金Acknowledgements This work was supported by the Chinese Academy of Sciences, the Research Institute of Petroleum Processing SINOPEC and the National Natural Science Foundation of China (Grant Nos. 20073043 and 29873050).
文摘A novel sol-gel process for preparing oxides and mixed oxides sols from precipitation and peptization process is reported in this article. Inorganic salts are used as raw materials in this study. It is found that the amount of acid has great influence on the stability and particle diameter distribution of the precursor sols. Ultrasonic treatment is used to prepare alumina sol at room temperature. The result of27Al NMR shows that there exist Al13 7+ species in the sol. By controlling the sol particles with narrow particle diameter distribution, alumina, titania and silica-alumina (SA) materials with narrow mesoporous distribution are formed by regular packing of sol particles during gelation without using any templates. The results also show that the structure and particle diameter distribution of precursor sol determine the final materials’ texture.
文摘Mesoporous （MSU） Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of the pH value on the formation of mesostructure and the thermal stability of the material has been evaluated. The products were characterized by transmission electron microscopy, powder X-ray diffraction and nitrogen adsorption-desorption measurements. The results showed that the as-prepared Ce0.5Zr0.5O2 mixed oxide possessed a specific surface area of 163.3 m^2·g^-1, which had a cubic fluorite-type structure and possessed specific surface areas of 148.4 and 62.4 m^2·g^-1 after calcination at 500 and 800 ℃ for 2 h, respectively. The material showed excellent thermal stability.
基金supported by NSFC(21066008)the Major Program of Natural Science Foundation of Inner Mongolia(2009ZD01)+1 种基金key scientific and technological project of Inner Mongolia(20101501)the Talented Person Foundation of Inner Mongolia and the Program Foundation for Coal Chemistry Preponderant Discipline of IMUT
文摘Platinated W/Zr mixed oxides supported on mesoporous silica with various amounts of Si/Zr, namely PtWO_3/ZrO_2（[76_TD$IF]x）-HMS, were prepared and studied for n-heptane isomerization reaction at 200–350 C. The various methods such as XRD, XRF, FT-IR, UV–vis DRS, NH_3-TPD, H_2 chemisorption, nitrogen adsorption–desorption, Py-IR, SEM and TGA techniques were used for characterization of these materials. Kinetics of n-heptane isomerization was also investigated under various hydrogen. n-Heptane pressures and the influence of reaction conditions on catalytic performance were studied. The ideal catalytic performance was observed on HMS with 0.6%Pt/12%WO_3/ZrO_2 and Si/Zr = 10.
