Journal ArticleDOI
Effect of synthesis pH and H2O molar ratio on the structure and morphology of aluminum phosphate (AlPO-5) molecular sieves
Chia-Ming Chen,Jih-Mirn Jehng +1 more
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TLDR
The structure and morphology of the AlPO-5 molecular sieves depend on the gel mixture's composition, hydrothermal temperature, and pH, and the formation rate of hexagonal pillar crystals to form a dense AlPO4 phase is favorable under acidic conditions, and an amorphous AlPO5 structure forms under basic conditions as mentioned in this paper.Abstract:
AlPO-5 molecular sieves were prepared by the hydrothermal reaction of a gel mixture with the following compositions: Al2O3 : P2O5 : Et3N : H2O = 1:1:1.5:x, where x is between 100 and 750 H2O molar ratio. The structure and morphology of the AlPO-5 molecular sieves depend on the gel mixture's composition, hydrothermal temperature, hydrothermal reaction time, and pH. Without pH control, the AlPO-5 structure changed from a spherical shape at H2O = 100 to a hexagonal pillar shape at H2O = 450. With pH control in the range of about 2.5-3.5, the hexagonal pillar crystals began to form at H2O = 100 and an island of hexagonal pillars with radiation form appeared at H2O = 300-450 due to the formation of a tridymite type of dense AlPO4 phase. It appears that the formation rate of hexagonal pillar crystals to form a dense AlPO4 phase is favorable under acidic conditions, and an amorphous AlPO-5 structure forms under basic conditions. Thus, the H2O concentration and pH value have a dramatic effect on the AlPO-5 structure.read more
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Influence of pH and Si content on Si incorporation in SAPO-5 and their catalytic activity for isomerisation of n-heptane over Pt loaded catalysts
Rafael Roldán,Rafael Roldán,Manuel Sánchez-Sánchez,Manuel Sánchez-Sánchez,Gopinathan Sankar,Francisco J. Romero-Salguero,César Jiménez-Sanchidrián +6 more
TL;DR: SAPO-5 samples have been synthesised using N-methyldicyclohexylamine as structure-directing agent (SDA) over a wide range of both Si content and pH values of the starting gel as discussed by the authors.
Journal ArticleDOI
Synthesis of Fe, Co, and Mn substituted AlPO-5 molecular sieves and their catalytic activities in the selective oxidation of cyclohexane
TL;DR: In this paper, the lattice expansions were observed with Fe, Co, and/or Mn substitution of Al atom in AlPO-5 molecular sieves, including FeAPO-5, CoAPO/Co/MnAPO5, and CoMn/CoMnOPO/AlPO/AlOPO5 were synthesized by hydrothermal method.
Journal ArticleDOI
Synthesis of hierarchical AlPO-n molecular sieves templated by saccharides
TL;DR: In this paper, a facile method for the synthesis of hierarchical AlPO-n molecular sieves (AlPO nH) templated by saccharides was reported.
Journal ArticleDOI
Preparation, characterization and reactivity of V- and/or Co-containing AlPO-18 materials (VCoAPO-18) in the oxidative dehydrogenation of ethane
TL;DR: The results obtained by the spectroscopic techniques employed in this paper suggest that V (V 5+ and VO 2+ ) and Co 2+ atoms are isomorphically incorporated into the aluminophosphate framework, although some vanadium is involved in an extra framework oxide, especially at high contents.
Journal ArticleDOI
The catalytic performance of methylation of naphthalene with methanol over SAPO-11 zeolites synthesized with different Si content
TL;DR: In this paper, a series of SAPO-11 zeolites with different Si contents were prepared by a hydrothermally synthesized method, and they were characterized by ICP, XRD, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD and 29Si MAS NMR.
References
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Infrared and Raman Spectra of Inorganic and Coordination Compounds
TL;DR: In this article, the normal modes of vibration are illustrated and corresponding vibrational frequencies are listed for each type, including diatomic, triatomic, fouratomic, five-atomic, six-atomic and seven-atomic types.
Journal ArticleDOI
Aluminophosphate molecular sieves: a new class of microporous crystalline inorganic solids
TL;DR: In this paper, a novel class of crystalline, microporous, aluminophosphate phases has been discovered that represents the first family of framework oxide molecular sieves synthesized without silica.
Journal ArticleDOI
Silicoaluminophosphate molecular sieves: another new class of microporous crystalline inorganic solids
Brent M. T. Lok,Celeste A. Messina,R. Lyle Patton,Richard Tadeusz Gajek,Thomas R. Cannan,Edith M. Flanigen +5 more
TL;DR: In this article, a nouvelle classe de tamis moleculaires, who peuvent etre utilises comme catalyseurs, supports de catalyseur, adsorbants ou echangeurs d'ions, correspondent a formule generale 0-0,3R•(Si x Al y P z )O 2 avec R=reste d'ammonium quaternaire ou une amine organique
Journal ArticleDOI
On synthesis conditions for tailoring AIPO4-5 crystal dimensions
TL;DR: In this article, the influence of the gel composition on the dimensions of AIPO4-5 crystals formed in the system Al2O3:P2O5:(C2H5)3N:H2O:HSO4 has been studied systematically.
Journal ArticleDOI
Conversion of alcohols (α-methylated series) on AlPO4 catalysts
TL;DR: In this article, the authors investigated the influence of reaction temperature on the selectivities of the products in 2-propanol and ethanol dehydration and showed a good correlation between the results of dehydration conversion and acid properties, gas-chromatographically measured through the irreversible adsorption of pyridine (473 and 573 K) and 2,6-dimethylpyridine(573 K).