12-磷钨酸插层MgAl水滑石的合成、表征及催化酯化原油脱酸性能

采用离子交换法合成了不同Mg/Al物质的量比的12-磷钨酸(H_3PW_(12)O_(40),HPW)插层水滑石(LDHs),采用XRD、FT-IR、Raman、ICP-AES、TG-DSC等分析手段表征其物化性质,Hammett指示剂-正丁胺滴定法测定其酸强度和酸量分布。进一步将其用于原油催化酯化脱酸反应,并与NO_3型LDHs对比,探讨酯化活性与催化剂性质之间的关系。结果表明,催化剂的活性主要受酸性和比表面积的影响。HPW插层LDHs的酯化活性明显优于NO3型LDHs,归因于增强的酸性和增大的比表面积。对于弱酸性的NO_3型LDHs,酯化活性与比表面积呈正向关系,Mg/Al物质的量比为4时,具有最大的比表面积和脱酸活性。而对于较强酸性的HPW插层LDHs,酯化活性主要受到酸量的影响,Mg/Al物质的量比为2的催化剂具有最高的酸量和脱酸活性。     

水滑石负载碳酸钾的微波法制备及其催化酯化原油脱酸性能

用微波法在水滑石上负载K₂CO₃,作为原油酯化脱酸催化剂。研究了浸渍法、超声波法、微波法和机械混合法四种制备方法,微波处理时间和K₂CO₃负载量对催化剂性质和活性的影响。结果表明,兼具高的水滑石结晶度,良好的K₂CO₃分散度和高碱量的催化剂有最佳脱酸活性。微波法在保持K₂CO₃高分散的同时明显缩短水滑石和K₂CO₃溶液的接触时间,从而保持水滑石的高结晶度,且有助于K与水滑石产生更多碱性中心,得到的催化剂脱酸活性最高。K₂CO₃负载量15%,微波处理5min制备的催化剂,在200℃,反应时间2h,催化剂和醇用量分别为原油质量的1%和2%时,对绥中高酸值原油的脱酸率可从水滑石的89.2%提高到97.7%。     

磷钨酸插层Zn/Al类水滑石催化合成邻苯二甲酸二(2-乙基)己酯

以对苯二甲酸根阴离子为预支撑体,制备了磷钨酸插层Zn/Al类水滑石杂化物催化剂,将其用于邻苯二甲酸二(2-乙基)己酯(DOP)的合成反应.研究了原料配比、催化剂用量、反应温度、反应时间等对邻苯二甲酸酐转化率的影响,及催化剂的可重复利用性.结果表明,磷钨酸-Zn/Al类水滑石杂化催化剂对DOP合成的催化效果较好,在催化剂用量为苯酐质量的0.76%,异辛醇与邻苯二甲酸酐的摩尔比为2.5,反应温度为180℃,反应时间为4.5 h,带水剂环己烷约为苯酐质量65%的反应条件下,苯酐转化率可达92.8%;反应10 h转化率可达97.9%.催化剂重复使用时转化率略有下降,经过乙醇洗涤再生,活性即可基本恢复.     

氟插层水滑石催化烯烃环氧化反应

制备了一系列不同Mg/Al比氟插层的水滑石(LDH-F),并用X射线衍射、傅里叶变换红外光谱、扫描电镜和BET比表面积检测法对催化剂进行了表征,考察了不同Mg/Al比的LDH-F在苯乙烯环氧化反应中的催化活性.结果表明,Mg/Al=5的LDH-F具有最佳催化活性.通过以乙腈和苯甲腈分别作为反应用腈的对比实验发现,苯甲腈的效果优于乙腈.以Mg/Al=5的LDH-F为催化剂,H2O2和苯甲腈为氧化剂对不同官能团化烯烃进行环氧化反应,结果表明,此催化体系具有良好的催化性能,在苯乙烯、茚、丙烯醇和烯丙基氯环氧化反应中转化率和选择性均在95%以上。     

谷氨酸插层水滑石吸附水中铅离子

采用共沉淀法合成了谷氨酸插层镁铝类水滑石(LDH),对所制备的试样进行了X-射线衍射和红外光谱表征,对LDH去除水中铅离子的能力进行了讨论,研究了吸附过程的吸附动力学和吸附等温线。结果表明,谷氨酸能嵌入镁铝水滑石的层间,该插层水滑石能有效吸附水中铅离子,吸附过程符合准二级动力学模型,吸附等温曲线可用Langmuir模型来描述,吸附量可达68.49mg/g。     

聚丙烯/插层改性水滑石纳米复合材料结构与性能研究

采用离子交换法制备了十二烷基磺酸钠和衣康酸共同改性水滑石(LDHs2),FTIR、XRD分析表明,十二烷基磺酸钠和衣康酸能够同时进入水滑石片层之间,层间距有很大提高。利用改性水滑石,通过马来酸酐-苯乙烯共接枝改性聚丙烯相容剂的熔融共混和聚丙烯与水滑石溶液共混制备母粒,然后与聚丙烯分别熔融共混两种方法制备聚丙烯/水滑石纳米复合材料。TEM分析表明,马来酸酐-苯乙烯共接枝改性聚丙烯作相容剂可以使水滑石在聚丙烯基体中达到更好分散。DSC、XRD分析表明,水滑石、相容剂以及短链共聚聚丙烯对聚丙烯晶型没有影响,但对其结晶速率、结晶度以及晶粒大小有所改变,复合材料中聚丙烯的起始结晶温度、结晶峰温度、结晶速率、结晶度均比纯聚丙烯高,晶粒粒径分布也更均匀。     

谷氨酸柱撑水滑石超分子结构层柱材料的插层组装

用返混沉淀方法实现了谷氨酸柱撑水滑石超分子结构层柱材料的插层组装,得到结晶度高、晶相单一且谷氨酸在层间有序排列的超分子结构层柱材料.用X射线衍射、原子光谱、元素分析、红外光谱及热重-差热分析表征了超分子结构层柱材料的结构,给出其结构模型.     

甲氨蝶呤柱撑水滑石超分子结构层柱材料的插层组装

用共沉淀和离子交换法将抗肿瘤类药物甲氨蝶呤(MTX)插层组装到水滑石层间,制备了一种新型的结晶度高、晶相单一且MTX在层间有序排列的超分子结构的药物-无机复合层柱材料.用XRD、原子光谱、元素分析、FT/IR、SEM及TG-DSC分析表征了超分子结构层柱材料的结构,并给出其结构模型.     

锌铝水滑石层板与层间离子调变及其光催化性能研究

采用双滴共沉淀法,结合水滑石层板阳离子和层间阴离子调变,制备十种锌铝水滑石,运用X射线衍射(XRD)、红外光谱(FT-IR)和差热分析(DTA)技术对合成样品的结构进行表征,考察了催化剂种类和用量、光照时间等变量对水滑石光催化降解罗丹明B的影响。研究结果表明,合成产物均具有典型水滑石特征衍射峰,调变阳离子种类合成的六种水滑石中,Zn-Al-Ni-CO₃-LDHs的催化效果最好;不同阴离子插层水滑石中,以ZnAl-CO₃-LDHs的光催化效果最佳;最佳反应条件为:催化剂用量0.1 g,光照时间65 min,两种水滑石材料光催化降解率可达82%以上。     

锂铝水滑石对水杨酸及其异构体的选择性插层研究

[LiAl_2(OH)_6]Cl·yH_2O was prepared by co-precipitation. The competitive intercalation of geometric isomers of hydroxybenzoic acid into the interlayer of layered double hydroxides (LDHs) was studied by the reaction of [LiAl_2(OH)_6]Cl·yH_2O with various mixtures of o-hydroxybenzoic acid, m-hydroxybenzoic acid and p-hydroxybenzoic acid. Powder X-ray diffraction (XRD) results confirmed the intercalation of the isomers, and high performance liquid chromatography (HPLC) was used for the quantitative study. The order of the preferential intercalation of the three isomers was found to be: o-hydroxybenzoic acid (1,2-C_7H_6O_3)》 p-hydroxybenzoic acid (1,4-C_7H_6O_3) > m-hydroxybenzoic acid (1,3-C_7H_6O_3).     

Preparation and thermal decomposition study of pyridinedicarboxylate intercalated layered double hydroxides

Supramolecular 2,3- and 2,5-pyridinedicarboxylate (PDC) intercalated ZnAl-layered double hydroxides (2,3- and 2,5-PDC–ZnAl–LDHs) have been prepared by ion exchange method. The structure and composition of the intercalated materials have been studied by X-ray diffraction (XRD) and inductively coupled plasma emission spectroscopy (ICP). The study indicates that the 2,3-PDC and 2,5-PDC anions are accommodated as interdigitated bilayer and monolayer arrangement respectively between the sheets of LDHs. Furthermore, their thermal decomposition processes were studied by the use of in situ high temperature X-ray diffraction (HT-XRD), and the combined technique of thermogravimetry-differential thermal analysis-mass spectrometry (TG-DTA-MS) under N2 atmosphere. Based on the comparison study on the temperatures of both decarboxylation and complete decomposition of interlayer PDC, it can be concluded that 2,5-PDC–ZnAl–LDHs has higher thermal stability than that of 2,3-PDC–ZnAl–LDHs.     

Preparation,characterization, structure‐property relationships,and thermal degradation kinetics of poly (lactic acid)/amidated potassium hydrogen phthalate intercalated layered double hydroxides nanocomposites

A novel nucleating agent, amidated potassium hydrogen phthalate intercalated layered double hydroxides (AP‐LDHs) were prepared using an amidation reaction. Through the structural characterization, it was found that AP‐LDHs had been successfully prepared. Meanwhile, the antibacterial activity of AP‐LDHs was studied. In order to improve the performance of poly (lactic acid) (PLA), PLA/AP‐LDHs nanocomposites were prepared by melt blending. Morphological analysis showed that PLA nanocomposites had an exfoliated structure. Mechanical properties test showed that the mechanical properties of PLA nanocomposites were enhanced. And the fracture scanning electron microscope analysis indicated that the PLA/AP‐LDHs nanocomposites exhibited ductile fracture characteristics. Moreover, differential scanning calorimetry and polarized optical microscopy analysis results demonstrated that the crystallization rate, nucleation density, and crystallinity of PLA/AP‐LDHs were improved. Thermogravimetric analysis and thermal degradation kinetics showed that the thermal stability of the PLA nanocomposites was significantly improved.     

用焙烧复原法插层组装有机层柱双氢氧化物

有机酸根插层双氢氧化物(简记为:LDHs OA)是制备具有特殊性质和功能的层柱材料的一类重要前驱体[1 3]。本文以Mg6Al2(OH)16CO2-3·6H2O(简记为MgAl CO2-3)和Zn6Al2(OH)16CO2-3·4H2O(简记为ZnAl CO2-3)为前体,用焙烧复原法将十四酸根(简记为14A)和十八酸根(简记为18A)分别插层组装到了MgAl LDHs和ZnAl LDHs层板间而制得了具有大的层间距、良好的结晶度和规整的层状结构的14A(18A)插层LDHs层柱材料(分别简记为MgAl 14A,mgAl 18A,ZnAl 14A,ZnAl 18A),用XRD谱、IR谱表征了插层交换产物的结构。1　实验部分1.1　仪…     

Preparation of a polymer monolith modified with delaminated layered double hydroxides for the microextraction of β‐agonists

In the present study, a novel poly(acrylamide‐co‐N‐isopropylacrylamide‐co‐ethylene dimethacrylate) monolithic column modified with saline‐modified delaminated layered double hydroxides was developed and exploited as the stationary phase in the polymer monolith microextraction of β‐agonists. Transmission electron microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, and thermal gravimetric analysis with derivative thermogravimetric determination were employed to characterize the monoliths. By coupling with high‐performance liquid chromatography determinations, extraction parameters affecting the extraction efficiency, including sample volume, flow rate, sample pH, eluent volume, and eluent flow rate were investigated with an orthogonal experiment design, L₁₆ (4⁵). Results demonstrated that under the optimal experimental conditions, low limits of detection in the range of 0.025–0.280 ng/mL were obtained with relative standard deviations in the range of 4.3–7.6% (intraday) and 6.7–8.8% (interday). When the developed method was applied to the analysis of β‐agonists in pork samples, recovery values were obtained in the range of 80.5−108.6%.     

2-羟基-4-甲氧基二苯甲酮-5-磺酸插层水滑石的制备及性能(英文)

以层状镁铝双金属氢氧化物(MgAlLayeredDoubleHydroxides,Mg-AlLDHs)为主体,以有机紫外光稳定剂2-羟基-4-甲氧基二苯甲酮-5-磺酸(BP)为客体,结合焙烧复原法和阴离子交换法合成了具有超分子结构有机-无机插层复合物(MgAl-BPLDHs),研究了层间阴离子、反应介质、pH值、反应时间等因素对于插层材料超分子结构的影响。用FTIR、XRD、TG-DTA、UV-Vis和粒度分析对其不同尺度的结构、热稳定性和紫外光稳定性等进行表征。结果表明,采用阴离子交换法难以进行插层反应;通过焙烧复原法可显著降低MgAl-LDHs层间CO2-离子,从而有利于BP阴离子交换进入MgAl-LDHs层间,在去离子水中,水温100℃,pH=7,反应时间为48h,BP过饱和的条件下合成得到最高插层率的MgAl-BP-LDHs;主体水滑石层板与客体以静电力和氢键相互作用,得到的超分子结构材料具有良好的热稳定及兼具优异的紫外屏蔽、吸收性能,是一种新型的有机-无机复合光热稳定剂。     

2-羟基-4-甲氧基二苯甲酮-5-磺酸插层水滑石的制备及性能

以层状镁铝双金属氢氧化物（MgAl Layered Double Hydroxides,Mg-Al LDHs）为主体,以有机紫外光稳定剂2-羟基-4-甲氧基二苯甲酮-5-磺酸（BP）为客体,结合焙烧复原法和阴离子交换法合成了具有超分子结构有机-无机插层复合物（MgAl-BP-LDHs）,研究了层间阴离子、反应介质、pH值、反应时间等因素对于插层材料超分子结构的影响。用FTIR、XRD、TG-DTA、UV-Vis和粒度分析对其不同尺度的结构、热稳定性和紫外光稳定性等进行表征。结果表明,采用阴离子交换法难以进行插层反应;通过焙烧复原法可显著降低MgAl-LDHs层间CO₂^-离子,从而有利于BP阴离子交换进入MgAl-LDHs层间,在去离子水中,水温100℃,pH=7,反应时间为48 h,BP过饱和的条件下合成得到最高插层率的MgAl-BP-LDHs;主体水滑石层板与客体以静电力和氢键相互作用,得到的超分子结构材料具有良好的热稳定及兼具优异的紫外屏蔽、吸收性能,是一种新型的有机-无机复合光热稳定剂。     

Synthesis of layered double hydroxides and their reactivities in 1-butene isomerization after calcination

Layered double hydroxides were synthesized and their catalytic activities tested in 1-butene isomerization after calcination at 723 K. The heat treatment destroyed the hydrotalcite-like structure creating mixed oxides with wide-ranging acid-base properties as revealed by temperature-programmed desorption of carbon dioxide and the double bond isomerization of 1-butene.     

Immobilization of anionic iron(III) porphyrins into ordered macroporous layered double hydroxides and investigation of catalytic activity in oxidation reactions

The first generation anionic iron(III) porphyrin [Fe(TSPP)] and the second generation anionic complexes [Fe(TDFSPP)], [Fe(TCFSPP)], and [Fe(TDCSPP)] were immobilized into three-dimensionally macroporous layered double hydroxide (3DM-LDH), using the direct reconstruction of 3DM-LDH from macroporous mixed oxides MOX or the anionic exchange on DDS intercalated 3DM-LDH. The macroporous layered double hydroxides were obtained at the surface of nanometric polystyrene spheres, which were synthesized by an inverse opal method. Polystyrene was removed after calcination in oxidizing atmosphere, nanostructured mixed oxides (3DM-MOX) were obtained, which after reconstruction give origin to macroporous layered double hydroxide (3DM-LDH). Following metalloporphyrin immobilization, the resulting materials were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), UV–vis (glycerin mull) spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR), and electron paramagnetic resonance (EPR). Results revealed that the complexes are either immobilized at the surface of the macroporous layered double hydroxide or intercalated between the layers, displacing some dodecylsufate anions. The obtained materials were investigated as catalysts for oxidation reactions, to find out whether they function as cytochrome P-450 models.     

铝基类水滑石和复合氧化物负载Pt催化剂的制备及对甲基苯酚加氢脱氧反应的催化性能

采用共沉淀法制备了多种铝基类水滑石,焙烧后得到对应的复合氧化物;以水滑石或复合氧化物为载体,制备了系列Pt基催化剂,研究了该催化剂对甲基苯酚加氢脱氧反应的催化性能。结果表明,Pt基催化剂的性能与载体的组分组成和结构相关;当以不经焙烧的类水滑石做载体时,所制备的Pt基催化剂具有较高的活性。其中,Pt-Ni-Al-H催化剂的加氢脱氧活性最高,对甲基苯酚转化率达到99.8%,甲苯选择性为1.4%,而Pt-Zn-Al-H催化剂的直接脱氧活性最高,在275℃和氢压2MPa下反应1h后,甲苯选择性达到84.1%。研究发现,反应过程中所生成的甲基环己烷可进一步发生脱氢反应转化为甲苯,说明所制备的Pt基催化剂具有较好的脱氢活性,可节省脱氧过程中的氢气消耗量。