CN101804973B - Aluminium phosphite microporous crystal material with organic-inorganic hybrid rings and synthetic method thereof - Google Patents

Abstract

The invention relates to an aluminum phosphite microporous crystal material (NKX-10) with an organic-inorganic hybrid ring and a preparation method. Its chemical formula can be expressed as [C ₄ H ₁₁ N ₂ ][Al(OH)(H(HPO ₃ )) ₂ ]. Using phosphorous acid as phosphorus source, piperazine as template, and adding hydrogen fluoride, it is synthesized by hydrothermal method. The microporous crystal material of the present invention has a two-dimensional spatial network structure composed of organic-inorganic hybrid rings and a one-dimensional inorganic long chain; the network structure array is between the Al-O-Al chains, and as the inorganic chains extend And arrange to form the spatial three-dimensional structure of NKX-10. The microporous material will have a wide range of applications in catalysis, ion exchange, and gas separation.

Description

Aluminum phosphite microporous crystal material with organic-inorganic hybrid ring and its synthesis method

technical field

The invention relates to the synthesis and structure of molecular sieves, in particular to an aluminum phosphite microporous crystal material (NKX-10) with an organic-inorganic hybrid ring and a synthesis method thereof.

technical background

Since the Harrison group reported the first synthesis of one-dimensional chain-like zinc phosphite with an organic template by a hydrothermal method in 2001 ^[1] , reports on new zinc phosphite materials and other new phosphite materials containing transition metal atoms and main group elements have been frequently reported . Including one-dimensional chain, two-dimensional layered, three-dimensional network structure, etc.; the pore size in the three-dimensional skeleton structure is from small 4-membered rings to large 24-membered rings. There are few reports on phosphite containing aluminum atoms, only two one-dimensional ^[2] , three three-dimensional aluminum phosphite ^[3] , and aluminum zinc phosphite ^[5] materials with aluminum atoms, and these In phosphate, only three materials have organic templates in the skeleton structure to balance the skeleton charge. In addition, studies have found that applying fluorine to pure aluminum phosphite materials can not only increase the growth of single crystals of microporous materials, but also generate new structures. The invention applies for an aluminum phosphite microporous crystal material with an organic-inorganic hybrid ring synthesized by fluorine and a synthesis method thereof.

Contents of the invention

The object of the present invention is to provide a novel aluminum phosphite microporous crystal material (abbreviated as NKX-10) with an organic-inorganic hybrid ring and a preparation method thereof. It has a phosphite microporous crystal material of aluminum metal elements, and has a three-dimensional spatial network structure composed of organic and inorganic hybrid rings. It will be widely used in adsorption, catalysis, ion exchange, and gas separation.

The aluminum phosphite microporous crystal material (abbreviated as NKX-10) with an organic-inorganic hybrid ring applied in the present invention has the following characteristic diffraction peaks in its x-ray powder diffraction pattern (as shown in Figure 1):

α＝90°，β＝90°，γ＝90°。NKX-10的不对称结构单元由32个晶体学独立的非氢原子组成(图2)。每个Al原子都是与六个氧原子配位形成AlO₆八面体，每个AlO₆八面体与相邻的AlO₆八面体共用处于顶点上的氧原子，这样的连接构成了沿[100]方向的无限Al-O-Al链；在沿Al-O-Al方向上，哌嗪分子上的N-H基团分别与无机亚磷酸铝长链上的两个O原子之间存在氢键作用，形成了有机无机杂化环，沿着与Al-O-Al长链近似垂直的方向排列成网状结构。(图3)此网状结构阵列随着无机链的延伸和排列形成NKX-10的空间网状结构。(图4)The aluminum phosphite microporous crystal material NKX-10 with an organic-inorganic hybrid ring, according to the results of single crystal analysis and elemental analysis, its chemical composition can be expressed as C ₃₂ H ₁₂₀ Al ₈ N ₁₆ O ₅₆ P ₁₆ , which belongs to Orthorhombic crystal system, the space group is P2 ₁ 2 ₁ 2, and its unit cell parameters are

α=90°, β=90°, γ=90°. The asymmetric structural unit of NKX-10 consists of 32 crystallographically independent non-hydrogen atoms (Fig. 2). Each Al atom coordinates with six oxygen atoms to form an AlO ₆ octahedron, and each AlO ₆ octahedron shares an oxygen atom at the apex with an adjacent AlO ₆ octahedron. Infinite Al-O-Al chains in the direction; along the Al-O-Al direction, there are hydrogen bonds between the NH groups on the piperazine molecule and the two O atoms on the inorganic aluminum phosphite long chain, forming The organic-inorganic hybrid rings are arranged in a network structure along the direction approximately perpendicular to the Al-O-Al long chain. (Figure 3) The network structure array forms the spatial network structure of NKX-10 along with the extension and arrangement of the inorganic chains. (Figure 4)

The preparation method of the present invention comprises the steps:

Mix aluminum source, phosphorus source, fluorine source, organic template agent and water evenly, stir at room temperature for 2 to 3 hours to make a uniform mixture, and hydrothermally crystallize at 140-160°C under autogenous pressure for 4 to 6 days ( In a stainless steel reaction kettle with polytetrafluoroethylene lining), the obtained crystals were washed with distilled water and suction filtered, and dried at 80°C to obtain the target product. The obtained product was well-crystallized and uniformly sized needle-like crystals.

The ratio of phosphorus source to aluminum source is 1.0-2.0, the ratio of organic template agent to aluminum source is 1.0-2.0, the ratio of water to phosphorus source is 50-100, and the ratio of hydrofluoric acid to aluminum source is 1.0 -2.0.

The aluminum source is pseudo-boehmite or aluminum hydroxide.

The phosphorus source is solid phosphorous acid, and the fluorine source is 40% hydrofluoric acid.

The organic template is anhydrous piperazine or hexahydrate piperazine.

The product obtained in the invention is the aluminum phosphite microporous crystal material NKX-10 with an organic-inorganic hybrid ring, which will have new and extensive applications.

Description of drawings

Fig. 1 is an x-ray powder diffraction pattern of a molecular sieve of the present invention.

Figure 2 is a diagram of the asymmetric structural unit of the molecular sieve.

Fig. 3 is the network structure along the c-axis direction of the molecular sieve.

Figure 4 is the spatial network structure of NKX-10 formed in the b-axis direction along with the extension and arrangement of the inorganic chains.

Detailed ways

Example 1, in a 100 milliliter beaker, 1.042 grams of pseudo-boehmite were dispersed in 10 milliliters of water, then 1.093 grams of phosphorous acid and 0.3 milliliters of 40% hydrofluoric acid were added, and stirred for 2 hours. Under stirring, 2 ml of water and 1.16 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, which was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, and crystallized at 160 ° C for 5 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. The product was characterized using the following instruments and methods:

1. Measure the x-ray powder diffraction pattern of the product using a German Bruker Diffracplus type x-ray diffractometer, and obtain a diffraction pattern (Fig. 1) with diffraction characteristic peaks as listed in Table 1.

3.14°≤2θ≤50°。属于正交晶系，空间群为P2₁2₁2，其晶胞参数为

α＝90°，β＝90°，γ＝90°，

Z＝1，T＝293(2)K，R(F)＝0.1079，wR(F²)＝0.2834。单晶数据及参数见表2、3，晶体结构见图2、3，4，(使用SHELXTL-97、Diamond 3.1软件绘制)。2. Select a crystal with a size of 0.20×0.06×0.04mm for single crystal structure analysis, collect single crystal diffraction data on a Bruker Smart CCD diffractometer, and use a graphite monochromator to monochromatize Mokα rays

3.14°≤2θ≤50°. It belongs to the orthorhombic crystal system, the space group is P2 ₁ 2 ₁ 2, and its unit cell parameters are

α=90°, β=90°, γ=90°,

Z=1, T=293(2)K, R(F)=0.1079, wR(F ² )=0.2834. The single crystal data and parameters are shown in Tables 2 and 3, and the crystal structures are shown in Figures 2, 3 and 4 (drawn using SHELXTL-97 and Diamond 3.1 software).

Table 1. X-ray powder diffraction characteristic peaks of NKX-10

Table 2. Crystal structure data of NKX-10

与键角(°)Table 3. Partial bond lengths in the crystal structure of NKX-10

and bond angle (°)

Symmetry operations for equivalent atomic generation:

#1x, y, z+1 #2x, y, z-1

Example 2, in a 100 milliliter beaker, 1.042 grams of pseudo-boehmite was dispersed in 10 milliliters of water, then 2.186 grams of phosphorous acid and 0.3 milliliters of 40% hydrofluoric acid were added, and stirred for 2 hours. Under stirring, 2 ml of water and 1.16 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, which was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner and crystallized at 140 ° C for 4 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. Every characterization and result are identical with example 1.

Example 3, in a 100 milliliter beaker, 1.042 grams of pseudo-boehmite were dispersed in 10 milliliters of water, then 1.093 grams of phosphorous acid and 0.45 milliliters of 40% hydrofluoric acid were added, and stirred for 2 hours. Under stirring, 2 ml of water and 0.87 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, which was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, and crystallized at 160 ° C for 5 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. Every characterization and result are identical with example 1.

Example 4 In a 100 ml beaker, 1.042 g of pseudo-boehmite was dispersed in 10 ml of water, then 1.640 g of phosphorous acid and 0.45 ml of 40% hydrofluoric acid were added and stirred for 2 hours. Under stirring, 2 ml of water and 1.16 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, and crystallized at 140 ° C for 5 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product.

Example 5 In a 100 ml beaker, 1.042 g of pseudoboehmite was dispersed in 10 ml of water, then 1.640 g of phosphorous acid and 0.3 ml of 40% hydrofluoric acid were added and stirred for 2 hours. Add 2 milliliters of water and 1.961 grams of piperazine hexahydrate successively under stirring, stir for 1 hour to form a uniform mixture, then transfer it to a stainless steel reaction kettle with a polytetrafluoroethylene liner, crystallize at 160 ° C for 5 days to obtain needles crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. Every characterization and result are identical with example 1.

Example 6, in a 100 ml beaker, 1.042 g of pseudoboehmite was dispersed in 12 ml of water, then 1.093 g of phosphorous acid, 0.3 ml of 40% hydrofluoric acid, 1.307 g of piperazine hexahydrate were added, and stirred for 3 hours , to form a homogeneous mixture, and then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, crystallized at 160 ° C for 6 days to obtain needle-shaped crystals, washed with distilled water and suction filtered, and dried at 80 ° C to obtain the target product. Every characterization and result are identical with example 1.

Example 7, in a 100 milliliter beaker, 1.040 grams of aluminum hydroxide were dispersed in 10 milliliters of water, then added 1.093 grams of phosphorous acid, 0.3 milliliters of 40% hydrofluoric acid, stirred for 2 hours. Under stirring, 2 ml of water and 1.16 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, which was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, and crystallized at 160 ° C for 5 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. Every characterization and result are identical with example 1.

Example 8, in a 100 milliliter beaker, 1.040 grams of aluminum hydroxide were dispersed in 10 milliliters of water, then added 1.640 grams of phosphorous acid, 0.45 milliliters of 40% hydrofluoric acid, stirred for 2 hours. Under stirring, 2 ml of water and 0.87 g of anhydrous piperazine were added successively, and stirred for 1 hour to form a homogeneous mixture, which was then transferred to a stainless steel reactor with a polytetrafluoroethylene liner, and crystallized at 160 ° C for 5 days to obtain needles. crystals, washed with distilled water, filtered with suction, and dried at 80°C to obtain the target product. Every characterization and result are identical with example 1.

Claims (3)

1. aluminium phosphite microporous crystal material NKX-10 with organic-inorganic hybrid rings is characterized in that the x ray powder diffraction pattern has following diffractive features peak:

2. according to the described aluminium phosphite microporous crystal material NKX-10 of claim 1, it is characterized in that this crystalline material has organic-inorganic hybrid rings, belong to rhombic system, spacer is P2 ₁2 ₁2, its unit cell parameters does

α=90 °, β=90 °, γ=90 °, the unsymmetrical structure unit of NKX-10 by 32 crystallography independently non-hydrogen atom form; Each Al atom all is to form AlO with six oxygen atom ligands ₆Octahedron, each AlO ₆Octahedra and adjacent AlO ₆The octahedra shared Sauerstoffatom that is on the summit, so unlimited Al-O-Al chain that has connected and composed edge [100] direction; Along on the Al-O-Al direction, there is hydrogen bond action in the N-H group on the piperazine molecule respectively and between two O atoms on the inorganic aluminum phosphite long-chain, has formed organic-inorganic hybrid rings, along being arranged in reticulated structure with the approximately perpendicular direction of Al-O-Al long-chain; The space three-dimensional structure that this reticulated structure has formed NKX-10 along with the extension and the arrangement of no chain.

3. the described preparation method with aluminium phosphite microporous crystal material NKX-10 of organic-inorganic hybrid rings of claim 1 is characterized in that it comprises following steps: aluminium source, phosphorus source, fluorine source, organic formwork agent and water are mixed; Described aluminium source is pseudo-boehmite or white lake, and said phosphorus source is a solid phosphorous acid, and the fluorine source is 40% hydrofluoric acid, and said organic formwork agent is Piperazine anhydrous or Uricida; The ratio in phosphorus source and aluminium source is 1.0-2.0, and the ratio in organic formwork agent and aluminium source is 1.0-2.0, and the ratio in water and phosphorus source is 50-100, and hydrofluoric acid in the ratio in aluminium source is: 1.0-2.0; At room temperature stirred 2-3 hour; Process uniform mixture; And in having the teflon-lined stainless steel cauldron under 140-160 ℃ of autogenous pressure hydrothermal crystallizing 4-6 days, the gained crystal obtains target product with distilled water wash and suction filtration after 80 ℃ of following dryings.

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