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Feng Deng - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Aluminophosphate Molecular Sieves in Alkaline Media.
Chemistry: A European Journal, 2020Co-Authors: Na Sheng, Feng Deng, Qianwen Zhu, Xin Hong, Juan Zhang, Junliang Sun, Zhaochi Feng, Liang WangAbstract:Unlike conventional aluminosilicate zeolites synthesized in alkaline media, aluminophosphate molecular sieves (AlPOs) have always been prepared under acidic conditions in the past three decades; this has been regarded as one of essential factors for synthesis, except for the case of silica-substituted analogues (SAPOs). For the first time, we demonstrate herein a simple and generalized route for synthesizing various types of aluminophosphate molecular sieves in alkaline media. A series of aluminophosphate sieves and their analogues have been prepared with different quaternary ammonium cations as structure-directing agents in this manner. The above successes have extended the systematic media from acidic or neutral to alkaline for the preparation of a series of aluminophosphate molecular sieves, which possibly open an alternative route for the synthesis of aluminophosphate molecular sieves.
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temperature dependence of the influence of the position 2 methyl group on the structure directing effect of piperazine in the synthesis of open framework Aluminophosphates
Scientific Reports, 2016Co-Authors: Pai Huang, Feng Deng, Wenfu YanAbstract:The temperature-dependence of the influence of the position-2-methyl group on the structure-directing effect of piperazine in the synthesis of open-framework Aluminophosphates was investigated. By heating the initial mixture with the composition of Al2O3:1.5 P2O5:R:125 H2O at 160 degrees C, where R is the structure-directing agent of 2-methylpiperazine or piperazine, layered Aluminophosphates APMeP150 (R = 2-methylpiperazine) and AP2pip (R = piperazine) were obtained. When the same initial reaction mixture was heated at 190 degrees C, layered Aluminophosphates APMeP200 (R = 2-methylpiperazine) and AP2pip (R = piperazine) were crystallized. APMeP200 and AP2pip have the same inorganic sheet topology. We investigated the crystallization processes of the four open-framework Aluminophosphates and found that increasing the heating temperature slowed the crystallization of the initial mixtures. The non-bonding interactions between the inorganic layers of the four open-framework Aluminophosphates and the experimental or theoretically generated structure-directing agents were calculated. The possible starting points of the crystallization of the four open-framework Aluminophosphates were analysed and compared. The temperature-dependence of the influence of the position-2-methyl group on the structure-directing effect of piperazine revealed that the structure-directing effect, the most important factor in the synthesis of zeolites and related open-framework materials, is determined by multiple factors. The structural parameters of the same compound can be affected by the synthesis conditions.
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molecular engineering of microporous crystals vi structure directing effect in the crystallization process of layered Aluminophosphates
Microporous and Mesoporous Materials, 2012Co-Authors: Xiaoqiang Tong, Wenfu Yan, Feng Deng, Liang Xin, Pai Huang, Chao Wang, Huai SunAbstract:The products of piperazine-directed synthesis of two-dimensional (20) Aluminophosphates, AP2pip and AIPO-CJ9, that were crystallized under different conditions for different periods of time were freeze-dried and characterized using XRD and NMR techniques. The core units of the layered Aluminophosphates including AP2pip, AIPO-CJ9, and L-DAP, which was hydrothermally synthesized in the presence of racemic 1,2-diaminopropane, were obtained by applying a "reverse evolution" process to their structures. The factors affecting the structure-directing ability of piperazine under acidic and basic conditions were analyzed. The cooperative role of water in directing the layered aluminophosphate of AP2pip under acidic conditions is discussed. After a thorough analysis of the core units of AIPO-CJ9 and L-DAP, a new phenomenon of a "topological-structure-directing effect" or a "topological-templating effect" was observed. The observation of the new phenomenon of a topological-structure-directing effect or a topological-templating effect may contribute to a deeper understanding of the nature or origin of the "structure-directing or templating effect". (C) 2012 Elsevier Inc. All rights reserved.
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Multinuclear solid-state NMR studies on phase transition of mesostructured aluminophosphate
Microporous and Mesoporous Materials, 2009Co-Authors: Wanling Shen, Lei Chen, Jun Yang, Hu Wei, Hailu Zhang, Qin Zou, Feng DengAbstract:The phase transition process from a hexagonal to a lamellar mesostructured aluminophosphate was studied by multinuclear solid-state NMR techniques in combination with low-angle XRD and elemental analysis measurements. The XRD result showed that after hydrothermal treatment for 9 h, the initial hexagonal phase began to transform to a lamellar phase. it was also found by NMR that some initially formed aluminophosphate was hydrolyzed during the earliest 2 In of the hydrothermal treatment, and the inorganic aluminophosphate framework became more and more condensed during the phase transition. The organic surfactant mainly has a gauche conformation in the hexagonal phase, whereas it mainly has a trans conformation in the lamellar phase and is packed more compactly. The Br(-) anion is found to be involved in the phase transition and likely enters into the interface to compensate the lost of negative charges that generated by the condensation of the aluminophosphate. Finally, a mechanism for the phase transition is proposed. (C) 2009 Elsevier Inc. All rights reserved.
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solid state nmr spectroscopy of anionic framework Aluminophosphates a new method to determine the al p ratio
Journal of Physical Chemistry B, 2006Co-Authors: Dan Zhou, Jun Xu, Jihong Yu, Lei Chen, Feng Deng, Ruren XuAbstract:A series of anionic framework Aluminophosphates, with different Al/P ratios, have been investigated by various solid-state NMR techniques, including 27Al, 31P magic angle spinning (MAS), 27Al → 31P cross polarization (CP), 27Al{31P} rotational echo double resonance (REDOR), and 31P{27Al} transfer of population double resonance (TRAPDOR). Different Al coordinations (AlO4b, AlO5b, and AlO6b) and P coordinations (PO4b, PO3bOt, PO2bO2t, and PObO3t), where b represents bridging oxygens and t represents terminal oxygens, can be unambiguously determined based on the solid-state NMR spectroscopy. Furthermore, a new method to determine the Al/P ratio of open-framework Aluminophosphates has been established, which is useful for the understanding of unknown aluminophosphate structures.
Wenqin Pang - One of the best experts on this subject based on the ideXlab platform.
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Mixed-bonded open-framework Aluminophosphates and related layered materials
Topics in Catalysis, 1999Co-Authors: Jiesheng Chen, Wenqin PangAbstract:The structural features, the synthesis and the role of templates in the synthesis for mixed-bonded open-framework Aluminophosphates and related layered materials will be reviewed in this article. These aluminophosphate materials differ from the (4,2)-connected Aluminophosphates and zeolites in that they contain TO5 and/or TO6 primary building units or terminal T-O bonds (T stands for Al or P). The extra ligands for the TO5 and TO6 units in the Aluminophosphates with framework Al/P = 1 are either bridging OH groups or H2O molecules in most cases whereas the terminal T-O bonds are either P-OH or P=O species with P=O bonds being prevalent in layered Aluminophosphates. Most of TO5 or TO6 containing Aluminophosphates are prepared using a cyclic amine or a diamine as the structure directing agent (template), and the Aluminophosphates with Al/P
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mixed bonded open framework Aluminophosphates and related layered materials
Topics in Catalysis, 1999Co-Authors: Jiesheng Chen, Wenqin PangAbstract:The structural features, the synthesis and the role of templates in the synthesis for mixed-bonded open-framework Aluminophosphates and related layered materials will be reviewed in this article. These aluminophosphate materials differ from the (4,2)-connected Aluminophosphates and zeolites in that they contain TO5 and/or TO6 primary building units or terminal T-O bonds (T stands for Al or P). The extra ligands for the TO5 and TO6 units in the Aluminophosphates with framework Al/P = 1 are either bridging OH groups or H2O molecules in most cases whereas the terminal T-O bonds are either P-OH or P=O species with P=O bonds being prevalent in layered Aluminophosphates. Most of TO5 or TO6 containing Aluminophosphates are prepared using a cyclic amine or a diamine as the structure directing agent (template), and the Aluminophosphates with Al/P<1 or the layered materials tend to form from an alcoholic medium. Both synthetic conditions and templates play a critical role in determining the composition and structural feature of these materials.
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THE CRYSTALLIZATION OF ALUMINOPHOSPHATE MICROPOROUS COMPOUNDS IN ALCOHOLIC SYSTEM
Proceedings from the Ninth International Zeolite Conference, 1993Co-Authors: Qisheng Huo, Wenqin PangAbstract:Syntheses of aluminophosphate microporous compounds, both zeolite-type and layered aluminophosphate materials containing organic amines, in the presence of various amines from alcohol media are described. The results of investigation into the crystallization of aluminophosphate from nonaqueous systems are preliminarily summarized. The influences of some main factors (organic amine template, alcohol solvent, crystallization temperature, time, etc.) on the resulting structures are studied.
Jiesheng Chen - One of the best experts on this subject based on the ideXlab platform.
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Mixed-bonded open-framework Aluminophosphates and related layered materials
Topics in Catalysis, 1999Co-Authors: Jiesheng Chen, Wenqin PangAbstract:The structural features, the synthesis and the role of templates in the synthesis for mixed-bonded open-framework Aluminophosphates and related layered materials will be reviewed in this article. These aluminophosphate materials differ from the (4,2)-connected Aluminophosphates and zeolites in that they contain TO5 and/or TO6 primary building units or terminal T-O bonds (T stands for Al or P). The extra ligands for the TO5 and TO6 units in the Aluminophosphates with framework Al/P = 1 are either bridging OH groups or H2O molecules in most cases whereas the terminal T-O bonds are either P-OH or P=O species with P=O bonds being prevalent in layered Aluminophosphates. Most of TO5 or TO6 containing Aluminophosphates are prepared using a cyclic amine or a diamine as the structure directing agent (template), and the Aluminophosphates with Al/P
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mixed bonded open framework Aluminophosphates and related layered materials
Topics in Catalysis, 1999Co-Authors: Jiesheng Chen, Wenqin PangAbstract:The structural features, the synthesis and the role of templates in the synthesis for mixed-bonded open-framework Aluminophosphates and related layered materials will be reviewed in this article. These aluminophosphate materials differ from the (4,2)-connected Aluminophosphates and zeolites in that they contain TO5 and/or TO6 primary building units or terminal T-O bonds (T stands for Al or P). The extra ligands for the TO5 and TO6 units in the Aluminophosphates with framework Al/P = 1 are either bridging OH groups or H2O molecules in most cases whereas the terminal T-O bonds are either P-OH or P=O species with P=O bonds being prevalent in layered Aluminophosphates. Most of TO5 or TO6 containing Aluminophosphates are prepared using a cyclic amine or a diamine as the structure directing agent (template), and the Aluminophosphates with Al/P<1 or the layered materials tend to form from an alcoholic medium. Both synthetic conditions and templates play a critical role in determining the composition and structural feature of these materials.
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Al16P20O80H4.4C6H18N2: A new microporous aluminophosphate containing intersecting 12- and 8-membered ring channels
Chemistry of Materials, 1998Co-Authors: Kazumasa Sugiyama, Jiesheng Chen, Kenji Hiraga, Osamu Terasaki, Shilun Qiu, Shan Zheng, Yasuhiro Sakamoto, Mark E. LightAbstract:A new microporous aluminophosphate, designated AlPO-HDA, is prepared under solvothermal conditions using 1,6-hexanediamine as the template. AlPO-HDA is the first microporous aluminophosphate with A...
Kazuyuki Kuroda - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of lamellar and hexagonal mesostructured Aluminophosphates using alkyltrimethylammonium cations as structure directing agents
Chemistry of Materials, 1999Co-Authors: Tatsuo Kimura, Yoshiyuki Sugahara, Kazuyuki KurodaAbstract:Lamellar and hexagonal mesostructured Aluminophosphates (AlPOs) were prepared and characterized. The lamellar mesostructured AlPO (APW-1) formed hydrothermally and the condensed framework was composed of alternating AlO4 and PO4 units. The hexagonal mesostructured AlPO (APW-2) is formed by transformation of a layered precipitate composed of both aluminophosphate oligomers and alkyltrimethylammonium (ATMA) cations. Calcined APW-2 had a mesoporosity with the BET surface area of 980 m2 g-1 and a pore diameter of 1.8 nm after substantial shrinkage of the framework. Lamellar APW-1 formed under most of the conditions surveyed, while hexagonal APW-2 was obtained under very restricted conditions. In this system, the charge matching in the products is the most important factor, although the assemblies of ATMA cations are essential as the structure-directing agents.
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synthesis of mesoporous Aluminophosphates using surfactants with long alkyl chain lengths and triisopropylbenzene as a solubilizing agent
Chemical Communications, 1998Co-Authors: Tatsuo Kimura, Yoshiyuki Sugahara, Kazuyuki KurodaAbstract:Mesostructured organo-Aluminophosphates were prepared by using surfactants with long alkyl chain lengths (C16 and C22) and by utilizing solubilization of triisopropylbenzene; calcination of the mesostructured materials yielded thermally stable mesoporous Aluminophosphates with surface areas >700 m2 g–1 and with pore diameters in the range 1.8–3.9 nm.
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Synthesis of mesoporous Aluminophosphates and their adsorption properties
Microporous and Mesoporous Materials, 1998Co-Authors: Tatsuo Kimura, Yoshiyuki Sugahara, Kazuyuki KurodaAbstract:Abstract Hexagonal mesostructured alkyltrimethylammonium–aluminophosphate materials were prepared by using hexadecyltrimethylammonium and dococyltrimethylammonium chlorides as surfactants and by utilizing 1,3,5-triisopropylbenzene as an auxiliary organic additive. Calcination of these materials at 600°C yielded thermally stable mesoporous aluminophosphate materials with large surface areas above 700 m2 g−1 and with pore diameters in the range from 1.8 to 3.9 nm. The hexagonal mesostructured materials before calcination had less condensed frameworks as determined by 31 P MAS NMR, which caused certain shrinkages during calcination for the formation of the porous structures. Water and benzene adsorption data indicated that the mesoporous aluminophosphate materials had comparatively hydrophilic mesopores.
Larry Kevan - One of the best experts on this subject based on the ideXlab platform.
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Substitution of transition metal ions into Aluminophosphates and silicoAluminophosphates: characterization and relation to catalysis
Research on Chemical Intermediates, 2002Co-Authors: Martin Hartmann, Larry KevanAbstract:The literature related to the incorporation of transition metal ions (TMI) into aluminophosphate (AlPO) and silicoaluminophosphate (SAPO) molecular sieves is reviewed. Microporous crystalline metal Aluminophosphates (MeAPOs) and metal silicoAluminophosphates (MeAPSOs) represent an important group of inorganic materials because of their high potential as adsorbents and catalysts. This review focuses mainly on the spectroscopic characterization of TMI containing MeAPOs and MeAPSOs covering the literature through 2000. The characterization of these materials is summarized and discussed in the light of possible isomorphous substitution of transition metal ions into the aluminophosphate framework. Moreover, the literature devoted to the use of these materials in catalysis and adsorption is reviewed.
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SYNTHESIS OF THERMALLY STABLE MESOPOROUS HEXAGONAL ALUMINOPHOSPHATE MOLECULAR SIEVES
Chemical Communications, 1997Co-Authors: Dongyuan Zhao, Zhaohua Luan, Larry KevanAbstract:Thermally stable mesoporous hexagonal Aluminophosphates (UHM-1) and silicoAluminophosphates (UHM-3) are synthesized based on ion-pair interactions of aluminophosphate species in the presence of tetramethylammonium hydroxide with a cationic surfactant [C 16 H 33 NMe 3 Cl].
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A novel aluminophosphate precursor that transforms to AlPO4-5 molecular sieve at high temperature
Chemical Communications, 1997Co-Authors: A. M. Prakash, Larry Kevan, Martin HartmannAbstract:A novel aluminophosphate microporous compound, denoted UHM-5, synthesized from an aqueous aluminophosphate gel at 150 °C in the presence of cyclohexylamine as the template, transforms upon calcination above 300 °C into AlPO4-5 molecular sieve.