An SOD-type metalloaluminophosphate molecular sieve (denoted as SOD-Mn) was ionothermally synthesized by introducing manganese(II) cations into the reaction mixture via MnO-acid or MnO2-reductant reactions. Composition and structure analyses results show that two kinds of manganese(II) cations exist in the SOD-Mn structure. Part of the manganese(II) cations isomorphously substitute the framework aluminum(III) with a substitution degree of ∼30%.
View Article and Find Full Text PDFHoneycomb-like AlPO4-11 macrostructures built of hollow tubular arrays have been directly achieved in a eutectic mixture. A time-dependent study reveals that the formation process obeys in situ epitaxial growth and phase transformation mechanisms.
View Article and Find Full Text PDFJ Colloid Interface Sci
August 2015
Extra-large-pore aluminophosphate -CLO (i.e., DNL-1) nanocrystals were synthesized in a eutectic mixture composed of diethylamine hydrochloride (DEAC) and ethylene glycol (EG) with 1-methylimidazole (1-MIm) as an additional amine using both conventional and microwave heating.
View Article and Find Full Text PDFA one-step hydrotreatment of vegetable oil combining deoxygenation and isomerization to directly produce low cloud point, high quality diesel is devised. The Pt/zeolite bifunctional catalysts prepared by using SAPO-11 and ZSM-22 zeolites as supports are used in this process. Catalytic reactions are conducted in a fixed-bed reactor under a hydrogen atmosphere.
View Article and Find Full Text PDFThe synthesis process of aluminophosphate AlPO(4)-11 molecular sieve in the mixed water/1-butyl- 3-methylimidazolium bromide ([bmim]Br) ionic liquid was investigated by XRD, multinuclear solid-state NMR, scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). It was observed that a tablet phase, named SIZ-2, was formed at the early stage of crystallization. During crystallization metastable SIZ-2 with an incompletely condensed framework phosphorus disappeared gradually, and the phosphorous species became fully condensed through hydroxyl reaction with tetrahedral aluminum to form thermodynamically stable AlPO(4)-11 in the final product.
View Article and Find Full Text PDFIn situ two-dimensional NMR and fluorescence emission spectroscopy were employed to investigate the cooperative structure-direction effect of organic amine such as morpholine in the synthesis of aluminophosphate molecular sieves in ionic liquids. In situ rotating frame nuclear Overhauser effect spectra (ROESY) together with fluorescence measurements demonstrate that the aggregates between imidazolium cations and morpholines through intermolecular hydrogen bonds can be formed in the gel during the crystallization of molecular sieves. Combining with the characterizations of the solid products by solid-state NMR, it is verified that different aggregates of organic amines with imidazolium cations, which is similar to self-assembled supramolecular analogues, could act as the structure-directing agents for selective tuning of the framework topologies such as AEL, AFI and LTA in the final solid products.
View Article and Find Full Text PDFCationic templating of imidazolium adjusted by the amine concentration in an ionothermal system results in products with larger channels or cage-like structures by reassembling the inorganic hosts around the changed organic guests.
View Article and Find Full Text PDFA combination of state-of-the art in situ one- and two-dimensional NMR spectroscopy and density functional theory (DFT) calculations have been employed for the first time to investigate the role of amines in the synthesis of aluminophosphate molecular sieves in ionic liquids (ILs). In situ rotating-frame nuclear Overhauser effect spectroscopy (ROESY) was used to demonstrate that the hybrid of imidazolium ionic liquids with organic amines, such as morpholine, connected through a hydrogen bond can be formed in the gel during the crystallization of molecular sieves. By combining the characterizations of the final solid products obtained by using XRD analyses, solid-state NMR spectroscopy, thermogravimetric analysis, and DFT calculation results, it was verified that the hybrid between morpholine and the imidazolium cation in the initial preparation stage can act as the structure-directing agent (SDA) for the synthesis of AFI-structured aluminophosphate molecular sieves.
View Article and Find Full Text PDFAlPO4-11 and AlPO4-5 molecular sieves are ionothermally prepared without addition of water by using anhydrous starting materials, such as NH4H2PO4, pseudoboehmite (AlOOH), and NH4F. The synthesis appears to be an autocatalytic process. Water has a remarkable effect on the synthesis process.
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