Mesoporous silicoaluminum pillared clays have been synthesized by one-potgallery-templated synthesis using organomontmorillonite, tetraethyl orthosilicate and aluminaisopropoxide as precursor. According to the charact...Mesoporous silicoaluminum pillared clays have been synthesized by one-potgallery-templated synthesis using organomontmorillonite, tetraethyl orthosilicate and aluminaisopropoxide as precursor. According to the characterization by powder X-ray diffraction(PXRD), thermogravimetric analysis (TGA), N2 adsorption isotherms and pyridine adsorptioninfrared (IR) techniques, the synthetic silicoaluminum pillared clays possess regular porosity withhigh thermal stability up to 750 ℃ and Br?nsted /Lewis acidity.展开更多
Volatile organic compounds （VOCs） are considered as a major pollutant in indoor and outdoor air. More stringent environmental regulations have been implemented in order to reduce the VOC emissions. One of the techni...Volatile organic compounds （VOCs） are considered as a major pollutant in indoor and outdoor air. More stringent environmental regulations have been implemented in order to reduce the VOC emissions. One of the techniques available for destructive removal of VOCs is catalytic oxidation. In the present work, Al/Rare Earths （REE： Y, Ce, La, Pr and Nd） pillared clays （PILCs） were used to support 0.2 wt.% of palladium for the complete oxidation of low concentration of benzene. The supports and catalysts were characterized by XRD, N2 adsorp- tiorddesorption, FTIR spectroscopy, HRTEM and H2-TPR techniques. The results indicated that after Al and Al/REE pillaring, the basal spacing, SBET, Amic and Vmic of Al and AIREE-PILC had a considerable increase compared with those of Na-mmt. Activity tests of deep oxidation of benzene showed that the catalytic activity of Pd catalysts supported on Al and AIREE-PILC were much higher than that on initial clays, which was due to the fact that optimized structure of PILCs, such as large basal spacing, high SBET and porosity, improved Pd dispersion and increased the active sites of Pd. Especially for Pd/AICe-PILC, the temperature of complete oxidation was about 280 ℃, exhibiting the highest catalytic activity.展开更多
The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the...The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the preparation of clays with intermediate compositions are also suggested.展开更多
基金Fund supported by the National Natural Science Foundation of China(No.20376075)Zhejiang Provincial Natural Science Foundation(No.201057)are acknowledged.
文摘Mesoporous silicoaluminum pillared clays have been synthesized by one-potgallery-templated synthesis using organomontmorillonite, tetraethyl orthosilicate and aluminaisopropoxide as precursor. According to the characterization by powder X-ray diffraction(PXRD), thermogravimetric analysis (TGA), N2 adsorption isotherms and pyridine adsorptioninfrared (IR) techniques, the synthetic silicoaluminum pillared clays possess regular porosity withhigh thermal stability up to 750 ℃ and Br?nsted /Lewis acidity.
基金Project supported by the Ministry of Science and Technology of China (2004 CB719504)the National Natural Science Foundation of China (20577043)
文摘Volatile organic compounds （VOCs） are considered as a major pollutant in indoor and outdoor air. More stringent environmental regulations have been implemented in order to reduce the VOC emissions. One of the techniques available for destructive removal of VOCs is catalytic oxidation. In the present work, Al/Rare Earths （REE： Y, Ce, La, Pr and Nd） pillared clays （PILCs） were used to support 0.2 wt.% of palladium for the complete oxidation of low concentration of benzene. The supports and catalysts were characterized by XRD, N2 adsorp- tiorddesorption, FTIR spectroscopy, HRTEM and H2-TPR techniques. The results indicated that after Al and Al/REE pillaring, the basal spacing, SBET, Amic and Vmic of Al and AIREE-PILC had a considerable increase compared with those of Na-mmt. Activity tests of deep oxidation of benzene showed that the catalytic activity of Pd catalysts supported on Al and AIREE-PILC were much higher than that on initial clays, which was due to the fact that optimized structure of PILCs, such as large basal spacing, high SBET and porosity, improved Pd dispersion and increased the active sites of Pd. Especially for Pd/AICe-PILC, the temperature of complete oxidation was about 280 ℃, exhibiting the highest catalytic activity.
文摘The synthesis of smectite clays is discussed. From literature studies the optimal ratios of precursor materials are suggested for the preparation of the four different basic forms of smectite clays. Conditions for the preparation of clays with intermediate compositions are also suggested.
