Synthesis of New Layered Double Hydroxide Intercalates

新型层状双氢氧化物插层物的合成

基本信息

批准号：
04045054
负责人：
NARITA Eiichi
金额：
$ 0.64万
依托单位：
Hachinohe National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1992
资助国家：
日本
起止时间：
1992 至无数据
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04045054/
关键词：
Layerd Double Hydroxide Hydrotalcite Intercalation Coprecipitation Intercalate Layered Compound Heteropolyoxometallate Silicate

项目摘要

Layered Double Hydroxides (LDHs),[NM^<2+>_xM^<3+>_<1-x>(OH)_2][A^<n->_<x/n>・yH_2O], consist of positively charged brucite-like layers separated by charge-balancing hydrated gallery anions A^<n->. In this study, polyoxometallate (POM)-pillared LDHs have been prepared by the new techniques.1. Preparation and characterization of silicate-intercalated LDHs via carboxylate-pillared precursorsIntercalation of silicate anions in gallery space of carboxylate-pillared LDH with different layer distance has been investigated by ion exchange method. The intercalation was carried out by adding a starting parent LDH in NaOH solution containing silicic acid granulas with vigorous stirring and by refluxing the reaction mixture at 100 ﾟCSilicate anions were found to be intercalated to from the silicated LDH with basal spacing of 11.4-12.1A^^ﾟ at the conditions of > O.O5 M NaOH and reaction time of 2.5 h. However, the interlayer structure of the silicated LDH was influenced with initial gallery height o … More f the parent LDH and the adipate-pillared LDH having a little bigger basal spacing [d_<003>=13.9A^^ﾟ) has givern the most well-ordered LDH product with two-dimensional silicate anions as the interlayer guest. The crystallinity of the sillicated LDH products was in order: adipate-pillared LDH [d_<003>=13.9A^^ﾟ) > terephthalate-pillared LDH (14.5A^^ﾟ) > sebacate-pillared LDH (16.8A^^ﾟ)> chlorinated LDH (7.8A^^ﾟ) > > laurate-pillared LDH (31.5A^^ﾟ). The silicated LDHs were also investigated by XRD, IR, TG-DTA, MAS-NMR etc.2. Direct synthesis of a polyoxometallate-pillared layered double hydroxide by copreciptationA new method for the preparation of POM-pillared LDH has been accomplished by using the corecipitation reaction as follows. First, alpha-[SiW_<11>O_<39>]^<8-> was dissolved in water and pH the POM solution was adjusted to6.0. Then, the mixed solution of Zn^<2+> and Al^<3+> ions was added drop-wise to the vigorously stirred POM solution at 100 ﾟC. The coprecipita-tion reaction of Zn^<2+> and Al^<3+> ions in moderately acidic alpha-[SiW_<11>O_<39>]^<8-> solution directly was found to afford a LDH derivative with an approxi-mate composition of [Zn_<24>Al_8(OH)_<64>][alpha-SiW_<11>O_<39>] and an exceptionally well-ordered gallery height of 9.8A^^ﾟ. Less

层状双氢氧化物 (LDH)，[NM^<2+>_xM^<3+>_<1-x>(OH)_2][A^<n->_<x/n>·yH_2O]，由以下组成带正电荷的水镁石层由电荷平衡水合阴离子 A^<n-> 分隔。在本研究中，多金属氧酸盐 (POM) 柱状 LDH 已通过新方法制备。 1.通过羧酸柱前驱体制备硅酸盐插层LDH并表征通过离子交换法研究了不同层距的羧酸柱LDH的通道空间中硅酸盐阴离子的插层。 LDH 在含有硅酸颗粒的 NaOH 溶液中剧烈搅拌并在 100 ℃下回流反应混合物在 > O.O5 M NaOH 和反应时间 2.5 h 的条件下，发现硅酸盐阴离子以 11.4-12.1A^^ﾟ的方式嵌入硅酸盐 LDH 中，但硅酸盐 LDH 的层间结构却受到影响。受到母体 LDH 和具有稍大基底间距的己二酸柱 LDH 的初始画廊高度的影响[d_<003>=13.9A^^ﾟ)给出了以二维硅酸盐阴离子为层间客体的最有序的LDH产物，硅化LDH产物的结晶度是有序的：己二酸柱LDH [d_<。 003>=13.9A^^ﾟ) > 对苯二甲酸酯柱LDH (14.5A^^ﾟ) > 癸二酸柱LDH (16.8A^^ﾟ)> 氯化LDH (7.8A^^ﾟ) > > 月桂酸柱LDH (31.5A^^ﾟ) 还研究了硅酸盐LDH。 XRD、IR、TG-DTA、MAS-NMR等2．多金属氧酸盐柱撑层状双氢氧化物通过共沉淀反应制备POM柱撑LDH的新方法如下：首先，溶解α-[SiW_<11>O_<39>]^<8->。将POM溶液的pH调节至6.0，然后滴加Zn 2+ 和Al 3+ 离子的混合溶液。 100℃下剧烈搅拌的 POM 溶液 Zn^<2+> 和 Al^<3+> 离子在中等酸性 α-[SiW_<11>O_<39>]^<8-> 中的共沉淀反应。发现直接溶液可提供 LDH 衍生物，其组成近似为[Zn_<24>Al_8(OH)_<64>][alpha-SiW_<11>O_<39>] 和异常有序的画廊高度为 9.8A^^ﾟ Less。