CN101391797A - Single anion pillared hydrotalcite and preparation method thereof - Google Patents

本发明提供的是一种单一阴离子柱撑水滑石及其制备方法。在室温下，按照M(II)/M(III)摩尔比为2－4的比例，分别称取M(II)(NO₃)₂·6H₂O和M(III)(NO₃)₃·9H₂O配制成硝酸盐水溶液；另取NaOH和Na₂CO₃配制成碱液，在强烈的磁力搅拌下，将上述碱液、硝酸盐水溶液同时逐滴等速加入到容器中，并滴至pH为10.0±0.5；将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h；干燥后的物质在450℃温度下焙烧2h，形成双金属氧化物；在N2保护下，将焙烧后的双金属氧化物置于装有具有单一阴离子溶液的容器，并放入恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥制得产品。本发明利用了水滑石的“记忆效应”，LDHs的层状结构重建，使阴离子进入层间从而形成新结构LDHs。The invention provides a single anion pillared hydrotalcite and a preparation method thereof. At room temperature, M(II)(NO ₃ ) ₂ ·6H ₂ O and M(III)(NO ₃ ) ₃ · 9H ₂ O to prepare nitrate solution; take NaOH and Na ₂ CO ₃ to prepare lye, under strong magnetic stirring, add the above lye and nitrate solution into the container drop by drop at the same speed, and drop to The pH is 10.0±0.5; the above mixed slurry is aged at 65°C for 8h, filtered, washed repeatedly until neutral, and dried in a vacuum oven at 70°C for 24h; the dried material is roasted at 450°C for 2h, Form a double metal oxide; under the protection of N2, place the roasted double metal oxide in a container with a single anion solution, put it into a constant temperature oscillator and vibrate at 180r/min for 24h, filter, wash two or three times, and then dry The product is obtained. The invention utilizes the "memory effect" of hydrotalcite, rebuilds the layered structure of LDHs, and makes anion enter the interlayer to form LDHs with new structure.

单一阴离子柱撑水滑石及其制备方法 Single anion pillared hydrotalcite and preparation method thereof

(一)技术领域 (1) Technical field

本发明涉及一种单一阴离子柱撑水滑石及其制备方法。The invention relates to a single anion pillared hydrotalcite and a preparation method thereof.

(二)背景技术 (2) Background technology

水滑石又称为双金属氢氧化物(Layered Double Hydroxides)，简写为LDHs。它是一类典型的阴离子层状材料，其主体一般是由两种或两种以上金属的氢氧化物构成类水镁石层，层板内离子间以共价键连接，层间阴离子以弱化学键与层板相连，起着平衡骨架电荷的作用。Hydrotalcite is also known as double metal hydroxide (Layered Double Hydroxides), abbreviated as LDHs. It is a typical anionic layered material. Its main body is generally composed of two or more metal hydroxides to form a brucite-like layer. The ions in the layer are connected by covalent bonds, and the anions between the layers are weak Chemical bonds are connected to the laminates and play a role in balancing the charge of the skeleton.

LDHs的一个重要性质是其层间阴离子的可交换性。各类阴离子如有机、无机、同多和杂多阴离子以及金属配合物阴离子通过离子交换都可以引入层间，由此得到了一大类所谓柱撑水滑石层柱材料。层间阴离子的可交换性取决于它们所带的电荷数及自身的性质。在一定条件下，某些功能性物种(原子、分子和离子)可以克服层状化合物层与层之间的作用力而可逆地插入层间空隙将层板距离撑开，并与层板形成较强的相互作用力而成为插层材料，形成一类具有层状结构的阴离子型超分子化合物(Katherine M.Tyner，Scott R.Schiffman，Emmanuel P.Giannelis，J.Controlled Release.95，501(2004))。水滑石独特的层状结构、二维孔道结构的可调变性及层间阴离子的可交换性，使其在催化、吸附、离子交换和功能助剂等方面具有巨大的应用潜力。An important property of LDHs is the exchangeability of their interlayer anions. All kinds of anions such as organic, inorganic, isopoly and heteropolyanions, and metal complex anions can be introduced into the interlayer through ion exchange, thus obtaining a large class of so-called pillared hydrotalcite layer materials. The exchangeability of interlayer anions depends on the number of charges they carry and their own properties. Under certain conditions, certain functional species (atoms, molecules, and ions) can overcome the force between layers of layered compounds and reversibly insert into the interlayer gap to spread the distance between the layers and form a relatively close relationship with the layers. Strong interaction force becomes intercalation material, forming a class of anionic supramolecular compounds with layered structure (Katherine M.Tyner, Scott R. Schiffman, Emmanuel P.Giannelis, J.Controlled Release.95, 501(2004 )). Hydrotalcite's unique layered structure, tunable two-dimensional pore structure and exchangeability of interlayer anions make it have great application potential in catalysis, adsorption, ion exchange and functional additives.

LDHs的另一特性是结构记忆效应。在一定温度下将LDHs的焙烧产物加入到含有所需阴离子的溶液中时，会发生LDHs的层状结构重建，阴离子进入层间从而形成新结构LDHs。焙烧复原法就是建立在LDHs的“结构记忆效应”特性基础上的。本法制备含有难以直接插层阴离子的LDHs，也多用于插入体积较大的客体分子(Wen ying Shi，Min Wei，Lan Jin，Congju Li，J.Molecular Catalysis B.47，58(2007))，焙烧复原法突出的优点是消除了与有机阴离子竞争插层的金属盐无机阴离子。而该法最重要的是选择适宜的焙烧温度，一般500℃以内重建LDHs的结构是可能的，焙烧时采用逐步升温法可提高LDOs的结晶度，若升温速率过快，CO₂和H₂O的迅速逸出会导致层结构被破坏。Another characteristic of LDHs is the structural memory effect. When the calcined products of LDHs are added to the solution containing the desired anions at a certain temperature, the layered structure reconstruction of LDHs will occur, and the anions will enter the interlayer to form new structural LDHs. The roasting recovery method is based on the "structural memory effect" characteristic of LDHs. This method prepares LDHs containing anions that are difficult to intercalate directly, and is also mostly used to insert larger guest molecules (Wen ying Shi, Min Wei, Lan Jin, Congju Li, J. Molecular Catalysis B.47, 58(2007)), The outstanding advantage of the roasting recovery method is that it eliminates the metal salt inorganic anion that competes with the organic anion for intercalation. The most important thing about this method is to choose an appropriate calcination temperature. Generally, it is possible to rebuild the structure of LDHs within 500°C. The crystallinity of LDOs can be improved by gradually increasing the temperature during calcination. If the heating rate is too fast, CO ₂ and H ₂ O The rapid escape will lead to the destruction of the layer structure.

近年来，对于水滑石的研究已成为材料科学领域的热点，人工合成的水滑石的层间阴离子并不是单一的，至少有两种阴离子组成(Z.Gu，A.C.Thomas，Z.P.Xu，J.H.Campbell，G.Q.Lu，Chem.Mater.20(11)，3715(2008)；T.Kameda，H.Takeuchi，T.Yoshioka，Separation and Purification Technology.62(2)，330(2008))。迄今为止尚未有过对单一阴离子(OH^-)柱撑水滑石的报道。In recent years, research on hydrotalcite has become a hot spot in the field of material science. The interlayer anions of artificially synthesized hydrotalcites are not single, but at least two kinds of anions (Z.Gu, ACThomas, ZPXu, JHCampbell, GQLu, Chem . Mater. 20(11), 3715(2008); T. Kameda, H. Takeuchi, T. Yoshioka, Separation and Purification Technology. 62(2), 330(2008)). So far, no single anion (OH ^- ) pillared hydrotalcite has been reported.

(三)发明内容 (3) Contents of the invention

本发明的目的在于提供一种能够制备出层间阴离子是单一的阴离子的单一阴离子(OH^-)柱撑水滑石。本发明的目的还在于提供一种单一阴离子(OH^-)柱撑水滑石的制备方法。The object of the present invention is to provide a single anion (OH ^- ) pillared hydrotalcite which can be prepared with a single anion between layers. The object of the present invention is also to provide a preparation method of single anion (OH ^- ) pillared hydrotalcite.

本发明的目的是这样实现的：The purpose of the present invention is achieved like this:

本发明的单一阴离子(OH^-)柱撑水滑石的化学结构通式为：[M(II)_1-xM(III)_x(OH)₂]^x+·A^n- _x/_n·mH₂O；其中M(II)是二价金属离子，为Mg²⁺、Fe²⁺、Co²⁺、Ni²⁺、Cu²⁺、Zn²⁺或Mn²⁺；M(III)是三价金属离子，为Al³⁺、Fe³⁺或Cr³⁺；An^-＝OH^-，x＝M³⁺/(M²⁺+M³⁺)，n为A的荷电量，m为结晶水数。The general chemical structure formula of the single anion (OH ^- ) pillared hydrotalcite of the present invention is: [M(II) _1-x M(III) _x (OH) ₂ ] ^x+ ·A ^n- _x / _n ·mH ₂ O ;wherein M(II) is a divalent metal ion, which is Mg ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ²⁺ or Mn ²⁺ ; M(III) is a trivalent metal ion , is Al ³⁺ , Fe ³⁺ or Cr ³⁺ ; An ^- ＝OH ^- , x＝M ³⁺ /(M ²⁺ +M ³⁺ ), n is the charge amount of A, and m is the crystal water number.

本发明的单一阴离子(OH^-)柱撑水滑石是采用这样的方法来制作的：The single anion (OH ^- ) pillared hydrotalcite of the present invention is made by the following method:

在室温下，按照M(II)/M(III)摩尔比为2-4的比例，分别称取M(II)(NO₃)₂·6H₂O和M(III)(NO₃)₃·9H₂O配制成硝酸盐水溶液，所述的M(II)是Mg²⁺、Fe²⁺、Co²⁺、Ni²⁺、Cu²⁺、Zn²⁺或Mn²⁺中的一种，所述的M(III)是Al³⁺、Fe³⁺或Cr³⁺中的一种；另取NaOH和Na₂CO₃配制成碱液(n(OH-)/[n(M²⁺)+n(M³⁺)]＝2.2，n(CO₃ ^2-)/[n(M²⁺)+n(M³⁺)]＝0.667)，在强烈的磁力搅拌下，将上述碱液、硝酸盐水溶液同时逐滴等速加入到容器中，并滴至pH为10.0±0.5；将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h；干燥后的物质在450℃温度下焙烧2h，形成双金属氧化物；在N₂保护下，将焙烧后的双金属氧化物置于装有具有单一阴离子溶液的容器，并放入恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥。At room temperature, M(II)(NO ₃ ) ₂ ·6H ₂ O and M(III)(NO ₃ ) ₃ · 9H ₂ O is formulated into nitrate aqueous solution, and the M(II) is one of Mg ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ²⁺ or Mn ²⁺ , so The above-mentioned M(III) is one of Al ³⁺ , Fe ³⁺ or Cr ³⁺ ; NaOH and Na ₂ CO ₃ are also used to make lye (n(OH-)/[n(M ²⁺ )+ n(M ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(M ²⁺ )+n(M ³⁺ )]=0.667), under strong magnetic stirring, the above lye, nitric acid Add the saline solution into the container drop by drop at a constant speed at the same time, and drop it until the pH is 10.0±0.5; age the above mixed slurry at 65°C for 8 hours, filter, wash repeatedly until neutral, and put it in a vacuum oven at 70°C Dry for 24 hours; the dried material is calcined at 450°C for 2 hours to form a double metal oxide; under the protection of _N2 , place the calcined double metal oxide in a container with a single anion solution, and put it into a constant temperature oscillation Vibrate in a container at 180r/min for 24h, filter, wash two or three times and dry.

所述的具有单一阴离子的溶液是水蒸气、脱CO₂的去离子水或NaOH溶液中的一种。The solution with a single anion is one of water vapor, CO ₂ deionized water or NaOH solution.

本发明利用了水滑石的“记忆效应”，将LDHs焙烧成层状双金属氧化物LDO，将LDO在期望插入的阴离子溶液中恢复其原来的层状结构，使阴离子进入层间从而形成新结构LDHs，实现插层组装的目的。该法可消除那些与期望插入的阴离子竞争插层的金属盐无机阴离子，而其它合成方法如共沉淀法、水热合成法、离子交换法，在制备过程中盐液多选择硝酸盐和氯化盐，这样层间就会引入部分的NO^3-和Cl^-离子，不易得到单一阴离子柱撑的水滑石。The invention utilizes the "memory effect" of hydrotalcite, roasts LDHs into layered double metal oxide LDO, restores the original layered structure of LDO in the anion solution expected to be inserted, and makes anion enter the interlayer to form a new structure LDHs, to achieve the purpose of intercalation assembly. This method can eliminate those metal salt inorganic anions that compete with the desired intercalated anions for intercalation, while other synthetic methods such as co-precipitation, hydrothermal synthesis, and ion exchange methods choose nitrate and chloride in the salt solution during the preparation process. Salt, so that part of NO ^3- and Cl ^- ions will be introduced between the layers, and it is not easy to obtain hydrotalcite supported by a single anion pillar.

(四)具体实施方式 (4) Specific implementation methods

下面举例对本发明做更详细地描述：The following examples describe the present invention in more detail:

实施例1：Example 1:

室温下，按Zn/Al摩尔比为3称取一定量的Zn(NO₃)₂·6H₂O和Al(NO₃)₃·9H₂O配制成硝酸盐水溶液200mL，另取一定量的NaOH和Na₂CO₃配制成200mL碱溶液，其中n(OH-)/[n(Zn²⁺)+n(Al³⁺)]＝2.2，n(CO₃ ^2-)/[n(Zn²⁺)+n(Al³⁺)]＝0.667。将上述碱液、盐液同时逐滴等速加入到1000mL三颈瓶中，滴至pH为10.0±0.5。将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h后，经450℃温度焙烧2h形成双金属氧化物。在N2保护下，将焙烧产物置于一定量的NaOH溶液中(用脱CO₂的去离子水配制)，并放入35℃恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥。At room temperature, weigh a certain amount of Zn(NO ₃ ) ₂ 6H ₂ O and Al(NO ₃ ) ₃ 9H ₂ O according to the Zn/Al molar ratio of 3 to prepare 200 mL of nitrate aqueous solution, and take another certain amount of NaOH and Na ₂ CO ₃ to make 200mL alkaline solution, where n(OH-)/[n(Zn ²⁺ )+n(Al ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(Zn ²⁺ )+n(Al ³⁺ )]=0.667. Add the above lye and salt solution into a 1000mL three-necked bottle at the same time drop by drop at a constant rate until the pH is 10.0±0.5. The above mixed slurry was aged at 65°C for 8h, filtered, washed repeatedly until neutral, dried in a vacuum oven at 70°C for 24h, and then calcined at 450°C for 2h to form a double metal oxide. Under the protection of N2, put the roasted product in a certain amount of NaOH solution (prepared with deionized water with _deCO2 ), and put it in a constant temperature oscillator at 35°C at 180r/min for 24h, filter, and wash two or three times dry.

实施例2：Example 2:

室温下，按Mg/Al摩尔比为2称取一定量的Mg(NO₃)₂·6H₂O和Al(NO₃)₃·9H₂O配制成硝酸盐水溶液200mL，另取一定量的NaOH和Na₂CO₃配制成200mL碱溶液，其中n(OH^-)/[n(Mg²⁺)+n(Al³⁺)]＝2.2，n(CO₃ ^2-)/[n(Mg²⁺)+n(Al³⁺)]＝0.667。将上述碱液、盐液同时逐滴等速加入到1000mL三颈瓶中，滴至pH为10.0±0.5。将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h后，经450℃温度焙烧2h形成双金属氧化物。在N₂保护下，将焙烧产物置于一定量的脱CO₂的去离子水中，并放入35℃恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥。At room temperature, weigh a certain amount of Mg(NO ₃ ) ₂ 6H ₂ O and Al(NO ₃ ) ₃ 9H ₂ O to prepare 200 mL of nitrate aqueous solution according to the Mg/Al molar ratio of 2, and take another certain amount of NaOH and Na ₂ CO ₃ to make 200mL alkaline solution, where n(OH ^- )/[n(Mg ²⁺ )+n(Al ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(Mg ²⁺ )+n(Al ³⁺ )]=0.667. Add the above lye and salt solution into a 1000mL three-necked bottle at the same time drop by drop at a constant rate until the pH is 10.0±0.5. The above mixed slurry was aged at 65°C for 8h, filtered, washed repeatedly until neutral, dried in a vacuum oven at 70°C for 24h, and then calcined at 450°C for 2h to form a double metal oxide. Under the protection of N ₂ , the roasted product was placed in a certain amount of de-CO ₂ deionized water, and placed in a constant temperature oscillator at 35°C at 180r/min for 24h, filtered, washed two or three times, and then dried.

实施例3：Example 3:

室温下，按Ni/Al摩尔比为3称取一定量的Ni(NO₃)₂·6H₂O和Al(NO₃)₃·9H₂O配制成硝酸盐水溶液200mL，另取一定量的NaOH和Na₂CO₃配制成200mL碱溶液，其中n(OH^-)/[n(Ni²⁺)+n(Al³⁺)]＝2.2，n(CO₃ ^2-)/[n(Ni²⁺)+n(Al³⁺)]＝0.667。将上述碱液、盐液同时逐滴等速加入到1000mL三颈瓶中，滴至pH为10.0±0.5。将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h后，经450℃温度焙烧2h形成双金属氧化物。在N₂保护下，采用养生法，将焙烧产物置于脱CO₂的去离子水的水蒸气中，同时振荡24h，过滤干燥。At room temperature, weigh a certain amount of Ni(NO ₃ ) ₂ 6H ₂ O and Al(NO ₃ ) ₃ 9H ₂ O according to the Ni/Al molar ratio of 3 to prepare 200 mL of nitrate aqueous solution, and take another certain amount of NaOH and Na ₂ CO ₃ to make 200mL alkaline solution, where n(OH ^- )/[n(Ni ²⁺ )+n(Al ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(Ni ²⁺ )+n(Al ³⁺ )]=0.667. Add the above lye and salt solution into a 1000mL three-necked bottle at the same time drop by drop at a constant rate until the pH is 10.0±0.5. The above mixed slurry was aged at 65°C for 8h, filtered, washed repeatedly until neutral, dried in a vacuum oven at 70°C for 24h, and then calcined at 450°C for 2h to form a double metal oxide. Under the protection of N ₂ , the roasted product was placed in the steam of deionized water with de-CO ₂ , shaken for 24 h at the same time, and dried by filtration.

实施例4：Example 4:

室温下，称取n(Co²⁺)/n(Ni²⁺)/n(Al³⁺)为3:3:2的Co(NO₃)₂·6H₂O，Ni(NO₃)₂·6H₂O，Al(NO₃)₃·9H₂O配制成硝酸盐水溶液200mL，另取一定量的NaOH和Na₂CO₃配制成200mL碱溶液，其中n(OH^-)/[n(Co²⁺)+n(Ni²⁺)+n(Al³⁺)]＝2.2，n(CO₃ ^2-)/[n(Co²⁺)+n(Ni²⁺)+n(Al³⁺)]＝0.667。将上述碱液、盐液同时逐滴等速加入到1000mL三颈瓶中，滴至pH为10.0±0.5。将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h后，经450℃温度焙烧2h形成双金属氧化物。在N₂保护下，将焙烧产物置于一定量的NaOH溶液中(用脱CO₂的去离子水配制)，并放入35℃恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥。At room ^temperature , _{weigh Co(NO 3} ⁾ ₂ ·6H ₂ O, Ni(NO ₃ ) ² _· 6H ₂ O, Al(NO ₃ ) ₃ 9H ₂ O was prepared into 200mL of nitrate aqueous solution, and another certain amount of NaOH and Na ₂ CO ₃ was prepared into 200mL of alkali solution, wherein n(OH ^- )/[n(Co ^{2 +} )+n(Ni ²⁺ )+n(Al ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(Co ²⁺ )+n(Ni ²⁺ )+n(Al ³⁺ )] = 0.667. Add the above lye and salt solution into a 1000mL three-necked bottle at the same time drop by drop at a constant rate until the pH is 10.0±0.5. The above mixed slurry was aged at 65°C for 8h, filtered, washed repeatedly until neutral, dried in a vacuum oven at 70°C for 24h, and then calcined at 450°C for 2h to form a double metal oxide. Under the protection of _N2 , put the roasted product in a certain amount of NaOH solution (prepared with deionized water _deCO2 ), and put it in a constant temperature oscillator at 35°C at 180r/min for 24h, filter, and wash two or three times After drying.

实施例5：Example 5:

室温下，称取n(Zn²⁺)/n(Ni²⁺)/n(Al³⁺)为3:3:2的Zn(NO₃)₂·6H₂ONi(NO₃)₂·6H₂O、Al(NO₃)₃·9H₂O配制成硝酸盐水溶液200mL，另取一定量的NaOH和Na₂CO₃配制成200mL碱溶液，其中n(OH^-)/[n(Zn²⁺)+n(Ni²⁺)+n(Al³⁺)]＝2.2，n(CO₃ ^2-)/[n(Zn²⁺)+n(Ni²⁺)+n(Al³⁺)]＝0.667。将上述碱液、盐液同时逐滴等速加入到1000mL三颈瓶中，滴至pH为10.0±0.5。将上述混合浆液于65℃温度下陈化8h，过滤，反复洗涤至中性，在70℃的真空干燥箱内干燥24h后，经450℃温度焙烧2h形成双金属氧化物。在N₂保护下，将焙烧产物置于一定量的脱CO₂的去离子水中，并放入35℃恒温振荡器中于180r/min振荡24h，过滤，洗涤两三次后干燥。At room temperature, weigh Zn(NO 3 ) 2 _· 6H 2 ONi(NO ₃ ) ₂ ·6H ₂ with n(Zn ²⁺ )/n ₍ Ni ²⁺ )/n(Al ³⁺ ) ratio 3:3: ₂ O, Al(NO ₃ ) ₃ ·9H ₂ O was prepared into 200mL of nitrate aqueous solution, and another certain amount of NaOH and Na ₂ CO ₃ was prepared into 200mL of alkali solution, wherein n(OH ^- )/[n(Zn ²⁺ ) +n(Ni ²⁺ )+n(Al ³⁺ )]=2.2, n(CO ₃ ^2- )/[n(Zn ²⁺ )+n(Ni ²⁺ )+n(Al ³⁺ )]=0.667 . Add the above lye and salt solution into a 1000mL three-necked bottle at the same time drop by drop at a constant rate until the pH is 10.0±0.5. The above mixed slurry was aged at 65°C for 8h, filtered, washed repeatedly until neutral, dried in a vacuum oven at 70°C for 24h, and then calcined at 450°C for 2h to form a double metal oxide. Under the protection of N ₂ , the roasted product was placed in a certain amount of de-CO ₂ deionized water, and placed in a constant temperature oscillator at 35°C at 180r/min for 24h, filtered, washed two or three times, and then dried.