A SAPO-11 silicoaluminophosphate molecular sieve with stable crystal structure was synthesized for the first time. After removing template by calcination, its crystal space group still retains Icm2 which the as-synthe...A SAPO-11 silicoaluminophosphate molecular sieve with stable crystal structure was synthesized for the first time. After removing template by calcination, its crystal space group still retains Icm2 which the as-synthesized has. The catalyst deriving from the present SAPO-11 materials shows higher isomerization selectivity and higher paraffin hydroisomerization yield than those reported elsewhere.展开更多
CoAPO11 molecular sieve with a high crystallinity was prepared by hydrothermal synthesis from a nonaqueous system(EG)in the presence of Et2NH or iPr2NH as a structuredirecting agent.The Xray diffraction(XRD)patterns a...CoAPO11 molecular sieve with a high crystallinity was prepared by hydrothermal synthesis from a nonaqueous system(EG)in the presence of Et2NH or iPr2NH as a structuredirecting agent.The Xray diffraction(XRD)patterns and scanning electron micrographs(SEM)revealed that the product powder was pure and homogenous in particlesize.The Xray powder diffraction data,compositional analysis,thermal stability analysis and UVVis diffuse reflectance spectroscopic analysis showed that Co()ions were incorporated in the aluminophosphate framework and tetrahedrally coordinated in the lattice of asprepared samples.展开更多
A TAPO-11 molecular sieve with the space group lcm2 was synthesized successfully. The samples with different space group were controlled simply only by adjusting the crystallization temperature （CT） in the hydrother...A TAPO-11 molecular sieve with the space group lcm2 was synthesized successfully. The samples with different space group were controlled simply only by adjusting the crystallization temperature （CT） in the hydrothermal system. In the system of gel with a molar composition of 0.7R- xTiO2： P2O5： Al2O3： 30H2O, where x is 0.01-0.10 and the R is a mixture of di-n-propylamine and diisopropylamine as templates. When CT was between 150-160℃, the calcined sample showed the space group of Icm^2, while it showed Pna21 at CT larger than 190℃. The characterizations of UV-Vis and FT-IR confirmed that Ti was incorporated into the AEL framework successfully.展开更多
To improve oil quality,ZSM-22/SAPO-11 composite molecular sieves were synthesized by adding ZSM-22 into a synthetic gel of SAPO-11 for n-decane hydroisomerization.The mass ratios of ZSM-22/(ZSM-22+SAPO-11)in the compo...To improve oil quality,ZSM-22/SAPO-11 composite molecular sieves were synthesized by adding ZSM-22 into a synthetic gel of SAPO-11 for n-decane hydroisomerization.The mass ratios of ZSM-22/(ZSM-22+SAPO-11)in the composite molecular sieves were optimized and the optimal ZSM-22/SAPO-11 composite(ZS-9)was obtained.The electrostatic repulsions between the ZSM-22 precursors and the SAPO-11 crystalline nuclei produced small ZSM-22 and SAPO-11 crystallites in ZS-9,which increased the specific surface area and mesopore volume and thereby exposed more acid sites.In comparison with conventional SAPO-11,ZSM-22 and their mechanical mixture,ZS-9 with smaller crystallites and the optimal medium and strong Brønsted acid centers(MSBAC)content displayed a higher yield of branched C_(10) isomers(81.6%),lower cracking selectivity(11.9%)and excellent stability.The correlation between the i-C_(10) selectivity and the MSBAC density of molecular sieves indicated that the selectivity for branched C_(10) isomers first increased and then decreased with increasing MSBAC density on the molecular sieves,and the maximum selectivity(87.7%)occurred with a density of 9.6×10^(−2)μmol m^(−2).展开更多
MAPO-11 molecular sieves were synthesized by hydrothermal methods. The influence of precursor of magnesium, Mg/Al ratio, synthesis temperature, synthesis time and the type of template on the formation and properties o...MAPO-11 molecular sieves were synthesized by hydrothermal methods. The influence of precursor of magnesium, Mg/Al ratio, synthesis temperature, synthesis time and the type of template on the formation and properties of MAPO-11 molecular sieves was examined. The samples were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric/differential thermogravimetric analysis (TG-DGA), etc. The results show that the shape and size of crystal were influenced by the precursor of Mg, the Mg/Al ratio and the type of template, and the TG-DGA analysis shows that MAPO-11 molecular sieves as-synthesized have poor thermal stability.展开更多
The preparation of two types of molecular sieves AlPO 4-11 and MAPO-11 is reported. The particle size of the latter is hundreds of microns, about 10 times larger than that of the former. The XRD, IR and DTA spectra h...The preparation of two types of molecular sieves AlPO 4-11 and MAPO-11 is reported. The particle size of the latter is hundreds of microns, about 10 times larger than that of the former. The XRD, IR and DTA spectra have demonstrated that magnesium has been introduced into the framework of AlPO 4-11. The successful preparation of large single crystal of MAPO-11 will open up a new area for the preparation of large molecular sieves crystals in the future. The large MAPO-11 crystal compound is a promising host for the host-guest assembly of composite materials.展开更多
文摘A SAPO-11 silicoaluminophosphate molecular sieve with stable crystal structure was synthesized for the first time. After removing template by calcination, its crystal space group still retains Icm2 which the as-synthesized has. The catalyst deriving from the present SAPO-11 materials shows higher isomerization selectivity and higher paraffin hydroisomerization yield than those reported elsewhere.
文摘CoAPO11 molecular sieve with a high crystallinity was prepared by hydrothermal synthesis from a nonaqueous system(EG)in the presence of Et2NH or iPr2NH as a structuredirecting agent.The Xray diffraction(XRD)patterns and scanning electron micrographs(SEM)revealed that the product powder was pure and homogenous in particlesize.The Xray powder diffraction data,compositional analysis,thermal stability analysis and UVVis diffuse reflectance spectroscopic analysis showed that Co()ions were incorporated in the aluminophosphate framework and tetrahedrally coordinated in the lattice of asprepared samples.
基金This work was supported by the National Natural Science Foundation of China （No. 20473027） Science and Technology Commission of Shanghai Municipality （No. 05dz22306）Pujiang project （No. 05PJ14041）.
文摘A TAPO-11 molecular sieve with the space group lcm2 was synthesized successfully. The samples with different space group were controlled simply only by adjusting the crystallization temperature （CT） in the hydrothermal system. In the system of gel with a molar composition of 0.7R- xTiO2： P2O5： Al2O3： 30H2O, where x is 0.01-0.10 and the R is a mixture of di-n-propylamine and diisopropylamine as templates. When CT was between 150-160℃, the calcined sample showed the space group of Icm^2, while it showed Pna21 at CT larger than 190℃. The characterizations of UV-Vis and FT-IR confirmed that Ti was incorporated into the AEL framework successfully.
基金The authors gratefully acknowledge the financial support of Science Foundation of China University of Petroleum,Beijing(Grant No.KYJJ2012-03-03).
文摘To improve oil quality,ZSM-22/SAPO-11 composite molecular sieves were synthesized by adding ZSM-22 into a synthetic gel of SAPO-11 for n-decane hydroisomerization.The mass ratios of ZSM-22/(ZSM-22+SAPO-11)in the composite molecular sieves were optimized and the optimal ZSM-22/SAPO-11 composite(ZS-9)was obtained.The electrostatic repulsions between the ZSM-22 precursors and the SAPO-11 crystalline nuclei produced small ZSM-22 and SAPO-11 crystallites in ZS-9,which increased the specific surface area and mesopore volume and thereby exposed more acid sites.In comparison with conventional SAPO-11,ZSM-22 and their mechanical mixture,ZS-9 with smaller crystallites and the optimal medium and strong Brønsted acid centers(MSBAC)content displayed a higher yield of branched C_(10) isomers(81.6%),lower cracking selectivity(11.9%)and excellent stability.The correlation between the i-C_(10) selectivity and the MSBAC density of molecular sieves indicated that the selectivity for branched C_(10) isomers first increased and then decreased with increasing MSBAC density on the molecular sieves,and the maximum selectivity(87.7%)occurred with a density of 9.6×10^(−2)μmol m^(−2).
文摘MAPO-11 molecular sieves were synthesized by hydrothermal methods. The influence of precursor of magnesium, Mg/Al ratio, synthesis temperature, synthesis time and the type of template on the formation and properties of MAPO-11 molecular sieves was examined. The samples were characterized by the techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric/differential thermogravimetric analysis (TG-DGA), etc. The results show that the shape and size of crystal were influenced by the precursor of Mg, the Mg/Al ratio and the type of template, and the TG-DGA analysis shows that MAPO-11 molecular sieves as-synthesized have poor thermal stability.
基金Supported by the National Natural Science Foundation of China(No. 2 99310 10 )
文摘The preparation of two types of molecular sieves AlPO 4-11 and MAPO-11 is reported. The particle size of the latter is hundreds of microns, about 10 times larger than that of the former. The XRD, IR and DTA spectra have demonstrated that magnesium has been introduced into the framework of AlPO 4-11. The successful preparation of large single crystal of MAPO-11 will open up a new area for the preparation of large molecular sieves crystals in the future. The large MAPO-11 crystal compound is a promising host for the host-guest assembly of composite materials.
