The large pore molecular sieves VPI-5 and Si VPI-5 were synthesized by using three organic amines (dipropylamine, diisopropylamine and dipentylamine) as the structure-directing agents. Compared with general alumlnopho...The large pore molecular sieves VPI-5 and Si VPI-5 were synthesized by using three organic amines (dipropylamine, diisopropylamine and dipentylamine) as the structure-directing agents. Compared with general alumlnophosphate molecular sieves, the synthesis of the molecular sieves of VPI-5 type ls of many unique features. Both VPI-5 and Si-VPI-5 were characterized by XRD, IR, TG-DTA, and MAS-NMR.展开更多
In this study,alkali/acid treatment and ion exchange post-synthesis modification methods to modify the pore diameter and structure of molecular sieve 13X(MS13X)were applied to obtain products,which could then be imple...In this study,alkali/acid treatment and ion exchange post-synthesis modification methods to modify the pore diameter and structure of molecular sieve 13X(MS13X)were applied to obtain products,which could then be implemented to improve the enrichment recovery of hopanoids in petroleum.The modification products were analyzed by SEM with EDS,XRD and nitrogen physisorption.The results indicated that the product which had been prepared in the oxalic acid ethanol solution formed some mesopores,and also retained the initial framework of crystal.It was revealed that this product was able to remarkably increase the recovery rate of hopanoids in petroleum without leading to a significant isotope fractionation phenomenon.It is thus shown that this modification method of non-aqueous oxalic acid solution for MS13X can be used as an effective pretreatment tool in the application of compoundspecific isotope analysis of hopanes with low concentration.展开更多
A novel Ce-Y/SBA-15 catalyst was prepared by modifying HY/SBA-15 microporous-mesoporous composite molecular sieve with cerium using the impregnation method. The characterization results from scanning electron microsco...A novel Ce-Y/SBA-15 catalyst was prepared by modifying HY/SBA-15 microporous-mesoporous composite molecular sieve with cerium using the impregnation method. The characterization results from scanning electron microscopy/energy dispersive X-ray dispersive spectroscopy（SEM/EDS）, transmission electron microscopy（TEM）, and X-ray fluorescence（XRF） studies indicated that the Ce-modified catalyst maintained the microporous-mesoporous structure of Y/SBA-15. The Ce ions were found to be uniformly dispersed in the pores of the molecular sieve without aggregation. The results from pyrolysis coupled-Fourier transform infrared spectroscopy（Pyridine-FTIR） and temperature programmed desorption of ammonia（NH3-TPD） showed that the loading of cerium caused the hydroxyl group in the catalyst to display stronger Bronsted acidity. The efficiency of the modified Ce-Y/SBA-15 catalyst was evaluated by using it to catalyze the synthesis of n-butyl acetate. The optimal synthesis conditions were determined by orthogonal experiments. The highest esterification yield of 94.4% was obtained when the reaction time was 2.0 h, with acid/alcohol molar ratio of 1：1.2, and catalyst loading of 10 wt.%. The results in this study demonstrated that the loading of cerium and the structure of Y/SBA-15 microporous-mesoporous composite molecular sieve helped in improving the catalytic activity of this acidic catalyst.展开更多
Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the ...Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the chemical composition of frameworks or loading alkali metal oxides/hydroxides owing to the special structure of zeolite. Through some novel methods展开更多
A Zn-containing aluminophosphate with ERI-zeotype structure was hydrothermally synthsized with 1,2-diaminocyclohexane（DACH） as the template. The result of the structural analysis indicates that the Zn-containing alu...A Zn-containing aluminophosphate with ERI-zeotype structure was hydrothermally synthsized with 1,2-diaminocyclohexane（DACH） as the template. The result of the structural analysis indicates that the Zn-containing aluminosphate crystallized in the hexagonal space group of P63/m was constituted up by the alternating AI（Zn）O4 and PO4 tetrahedra. The organic amine DACH located in the ERI cages was used to balance the negative charge of the framework.展开更多
基金Supported by the National Natural Science Foundation of China
文摘The large pore molecular sieves VPI-5 and Si VPI-5 were synthesized by using three organic amines (dipropylamine, diisopropylamine and dipentylamine) as the structure-directing agents. Compared with general alumlnophosphate molecular sieves, the synthesis of the molecular sieves of VPI-5 type ls of many unique features. Both VPI-5 and Si-VPI-5 were characterized by XRD, IR, TG-DTA, and MAS-NMR.
基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA14010101)the National Natural Science Foundation of China(NNSFC,Project No.41473020)PetroChina Science and Technology Projects(Grants 2019A-0208)for supporting this research project.
文摘In this study,alkali/acid treatment and ion exchange post-synthesis modification methods to modify the pore diameter and structure of molecular sieve 13X(MS13X)were applied to obtain products,which could then be implemented to improve the enrichment recovery of hopanoids in petroleum.The modification products were analyzed by SEM with EDS,XRD and nitrogen physisorption.The results indicated that the product which had been prepared in the oxalic acid ethanol solution formed some mesopores,and also retained the initial framework of crystal.It was revealed that this product was able to remarkably increase the recovery rate of hopanoids in petroleum without leading to a significant isotope fractionation phenomenon.It is thus shown that this modification method of non-aqueous oxalic acid solution for MS13X can be used as an effective pretreatment tool in the application of compoundspecific isotope analysis of hopanes with low concentration.
基金Project supported by the Research Fund for the Doctoral Program of Higher Education(20100042110008)the Talent Scientific Research Fund of Liaoning Shihua University
文摘A novel Ce-Y/SBA-15 catalyst was prepared by modifying HY/SBA-15 microporous-mesoporous composite molecular sieve with cerium using the impregnation method. The characterization results from scanning electron microscopy/energy dispersive X-ray dispersive spectroscopy（SEM/EDS）, transmission electron microscopy（TEM）, and X-ray fluorescence（XRF） studies indicated that the Ce-modified catalyst maintained the microporous-mesoporous structure of Y/SBA-15. The Ce ions were found to be uniformly dispersed in the pores of the molecular sieve without aggregation. The results from pyrolysis coupled-Fourier transform infrared spectroscopy（Pyridine-FTIR） and temperature programmed desorption of ammonia（NH3-TPD） showed that the loading of cerium caused the hydroxyl group in the catalyst to display stronger Bronsted acidity. The efficiency of the modified Ce-Y/SBA-15 catalyst was evaluated by using it to catalyze the synthesis of n-butyl acetate. The optimal synthesis conditions were determined by orthogonal experiments. The highest esterification yield of 94.4% was obtained when the reaction time was 2.0 h, with acid/alcohol molar ratio of 1：1.2, and catalyst loading of 10 wt.%. The results in this study demonstrated that the loading of cerium and the structure of Y/SBA-15 microporous-mesoporous composite molecular sieve helped in improving the catalytic activity of this acidic catalyst.
文摘Progress on preparing strong basic and superbasic zeolites, mainly obtained in China during last decade has been reviewed. Strong basic sites are difficult to be generated on zeolite by common way, e.g. adjusting the chemical composition of frameworks or loading alkali metal oxides/hydroxides owing to the special structure of zeolite. Through some novel methods
文摘A Zn-containing aluminophosphate with ERI-zeotype structure was hydrothermally synthsized with 1,2-diaminocyclohexane（DACH） as the template. The result of the structural analysis indicates that the Zn-containing aluminosphate crystallized in the hexagonal space group of P63/m was constituted up by the alternating AI（Zn）O4 and PO4 tetrahedra. The organic amine DACH located in the ERI cages was used to balance the negative charge of the framework.
