Effect of Water on the Ionothermal Synthesis of Molecular Sieves

Ma, Huaijun; Tian, Zhijian; Xu, Runsheng; Wang, Bingchun; Wei, Ying; Wang, Lei; Xu, Yunpeng; Zhang, Weiping; Lin, Liwu

doi:10.1021/ja802207p

Cited by 113 publications

(95 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tian and co-workers investigated the effect of water on the ionothermal synthesis of aluminophosphate molecular sieves AlPO 4 -5 and AlPO 4 -11. [341] Their work demonstrates that water has a pronounced effect on the ionothermal synthesis of molecular sieves. Addition of reagent amounts of water can enhance the crystallization kinetics Figure 12.…”

Section: Open-framework Structuresmentioning

confidence: 99%

Preparation of Inorganic Materials Using Ionic Liquids

2009

View full text Add to dashboard Cite

Conventional synthesis of inorganic materials relies heavily on water and organic solvents. Alternatively, the synthesis of inorganic materials using, or in the presence of, ionic liquids represents a burgeoning direction in materials chemistry. Use of ionic liquids in solvent extraction and organic catalysis has been extensively studied, but their use in inorganic synthesis has just begun. Ionic liquids are a family of non-conventional molten salts that can act as templates and precursors to inorganic materials, as well as solvents. They offer many advantages, such as negligible vapor pressures, wide liquidus ranges, good thermal stability, tunable solubility for both organic and inorganic molecules, and much synthetic flexibility. In this Review, the use of ionic liquids in the preparation of several categories of inorganic and hybrid materials (i.e., metal structures, non-metal elements, silicas, organosilicas, metal oxides, metal chalcogenides, metal salts, open-framework structures, ionic liquid-functionalized materials, and supported ionic liquids) is summarized. The status quo of the research field is assessed, and some future perspectives are furnished.

show abstract

Section: Open-framework Structuresmentioning

confidence: 99%

Preparation of Inorganic Materials Using Ionic Liquids

2009

View full text Add to dashboard Cite

show abstract

“…It was found that the intensity of tetrahedral Al increased followed by the decrease of the octahedral Al, and the intensity of fully condensed P increased followed by the decrease of partially condensed P as the crystallization time increased. As for the 12 h sample, nearly all the Al and P atoms sit in the zeolitic framework as AlO 4 and PO 4 tetrahedrons, and are connected through the Al-O-P bonds as indicated by the 2D 27 Al, 31 P heteronuclear correlation (HETCOR) spectra.…”

Section: Resultsmentioning

confidence: 96%

“…C CP/MAS NMR spectra were recorded at 100.5 MHz with a spinning rate of 4 kHz, 2100 scans, a contact time of 2.5 ms, and a recycle delay of 2 s. 27 Al MAS NMR spectra were recorded at 104.2 MHz with a spinning rate of 10 kHz, 200 scans, and a 2 s recycle delay. The chemical shifts were referenced to a 1 % AlA C H T U N G T R E N N U N G (NO 3 ) 3 aqueous solution.…”

mentioning

confidence: 99%

New Insights into the Role of Amines in the Synthesis of Molecular Sieves in Ionic Liquids

Zhang

Guan

et al. 2009

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

A 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. Our findings may suggest a synthesis mechanism of molecular sieves in ionic liquids in which the IL-organic amine hybrid is required in the nucleation step, whereas the crystal growth occurs through the occlusion of ionic liquids in the zeolite channels.

show abstract

“…离子热合成法采用离子液体作为溶剂和结构导向剂, 可在常压下实现分子筛的晶化合成 [9] . 在离子热合成磷酸铝分子筛的过程中, 氟离子兼具矿化剂和结构导向剂的作用 [16] . 而上述结果表明, 在离子热自转晶合成 AEL 膜的过程中, 氟离子不但促进分子筛膜晶体的成核和生长, 而且还影响了分子筛膜的生长取向.…”

unclassified

“…P 物种是 AEL 磷酸铝分子筛骨架的组成部分之一, 磷酸铝分子筛骨架由铝氧四面体和磷氧四面体严格交替组成, 磷铝比为 1∶1 [17] ; 成膜所需的 P 物种的量相对较多; 而 F -在磷酸铝分子筛的晶化过程中起矿化剂和结构导向剂的作用 [16] , 合成过程所需 F -的量相对较少. 由图 5, 6 可知, 由基底从第一步反应中携带入第二步反应的少量 P 物种, 无法满足分子筛膜的合成所需; 而基底从第一步反应中携带的少量 F -, 即可满足分子筛膜的合成所需.…”

unclassified

Ionothermal Synthesis of AEL-Type Aluminophosphate Molecular Sieve Membrane and Its Formation Mechanism

Li¹,

Li²,

Wang³

et al. 2013

Acta Chim. Sinica

Self Cite

View full text Add to dashboard Cite

Highly c-oriented AEL aluminophosphate molecular sieve membranes were ionothermally synthesized on the surface of δ-alumina substrate by "Substrate Surface Conversion" method. The typical synthesis procedure can be described as follows: a δ-aluminia alumina disc was put into 1-ethyl-3-methyl imidazolium bromide ([EMIm]Br) solution containing reagent quantities of phosphoric acid (H 3 PO 4 ) (85 wt% in water, AR) and hydrofluoric acid (HF) (40 wt% in water, AR). The synthesis was performed at 210 ℃ for certain time. No additional Al source is added into the synthesis solution. After the synthesis, the as-synthesized sample was washed thoroughly with distilled water and acetone for several times by ultrasonic vibration and dried at 120 ℃ overnight. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out to characterize the products. The synthesis process of AEL membrane via "Substrate Surface Conversion" can be divided into two separated steps, which is carried out in the ionic liquid solution of HF and H 3 PO 4 in turn. We termed this route as ionothermal two-step method, which making it possible for us to investigate the effect of HF and H 3 PO 4 , respectively. The formation mechanism of "Substrate Surface Conversion" was therefore demonstrated, with which the δ-alumina substrate acts as both support and Al source during the synthesis process. The surface of the substrate is first converted into a gel layer by the solution. The layer is a heterogeneous phase, which contains all nutrients required for the crystallization of molecular sieve membrane, including the aluminophosphate precursor, the mineralizer and the structure directing agent. The transformation from the gel layer into membrane is probably of solid-solid formation mechanism. The whole synthesis process needs the participation of both H 3 PO 4 and HF. H 3 PO 4 is an essential component of both aluminophosphate precursor and molecular sieve crystal. The crystallinity and the orientation of synthesized membranes can be greatly influenced by adjusting the amount of HF in the initial solution, which may act as both structure directing agent and mineralizer during the synthesis process of molecular sieve membrane.

show abstract

Effect of Water on the Ionothermal Synthesis of Molecular Sieves

Cited by 113 publications

References 28 publications

Preparation of Inorganic Materials Using Ionic Liquids

Preparation of Inorganic Materials Using Ionic Liquids

New Insights into the Role of Amines in the Synthesis of Molecular Sieves in Ionic Liquids

Ionothermal Synthesis of AEL-Type Aluminophosphate Molecular Sieve Membrane and Its Formation Mechanism

Contact Info

Product

Resources

About