【作者】 孙炜岩；

【导师】 李占双；

【作者基本信息】 哈尔滨工程大学 ， 应用化学， 2007， 硕士

【摘要】 层状金属氢氧化物是由两种或两种以上金属离子组成，具有层状晶体结构的氢氧化物（HTLCs），以其为主体，将功能性分子或离子作为客体插入（或组装）到层间，可以改进HTLCs作为催化剂及载体的性能。由于HTLCs的化学组成和结构在微观上具有可调控性，使得HTLCs在作为催化剂或催化剂载体、纳米反应器、电流变材料、导电材料、离子交换剂、污水处理、基因药物载体、光电活性材料的捕获与可控释放等方面都具有广阔的应用前景，日益引起人们的关注。本论文采用水热法将磁性基质与三元类水滑石组装制备二维层状磁性类水滑石，旨在合成一种在不影响催化剂催化性能的前提下，有利于控制、分离和回收的催化剂及催化剂载体材料。着重研究了反应温度、pH值、晶化温度、磁性基质含量及焙烧温度对磁性水滑石的结构、纯度、结晶度和磁学性能的影响。并借助XRD、IR、TG-DSC、TEM、HRTEM、SEM、VSM等手段对其进行了表征。以期从这些表征结果中筛选出制备此种材料的最佳条件。实验结果表明：一定量磁性基质的引入没有改变水滑石典型层状结构，XRD图谱显示磁性水滑石仍具有水滑石特征衍射峰，保持磁性基质引入量等于10 mL时可制备出既不影响水滑石晶体结构又具有良好磁性的可作为催化剂载体材料的磁性水滑石；HRTEM照片中的晶格条纹相及FFT出现的衍射斑点都能说明晶体沿（003），（006），（110）晶面方向生长良好；N₂吸附／脱附实验结果表明所制备的三元磁性类水滑石有较高的比表面积和较小的孔径分布，ZNA-MHTL-10经400℃焙烧样品的S_BET值达到170 m²／g，对应的平均孔径d_P为6.007 nm，而且磁学性能良好，满足作为催化剂及催化剂载体的要求。利用水滑石具有“记忆效应”的特性将在一定温度范围内焙烧后的样品在初始反应条件下进行塌陷结构的复原实验，实验结果表明：在较低的焙烧温度下，由于产物是亚稳态的混合氧化物，此时层状结构的恢复存在可能性，在较高的焙烧温度下，产物是稳定的复合尖晶石类氧化物，此时塌陷结构已经无法进行复原。更多还原

【Abstract】 Layered metal hydroxide is used to designate the lamellar hydroxides with two or more kinds of metallic cations in the main layers. The catalysts and catalyst carriers were obtained with new function by selecting one or more functional guest molecules to insert the interior of host HTLCs. HTLCs host layers can supply various cationic frameworks and have an absence of long-range cation ordering. HTLCs and their calcined production have recently attracted intense interest owing to their potential technological applications such as catalysts or catalyst carriers, anionic exchangers, antacids, the treatment of the waste water, antisettling agents, separation and membrane technology, filtration, processing of selective chemical nanoreactors, scavenging and controlled release of anions, medicine, electroactive and photoactive materials, etc.In this thesis, ternary layered magnetic hydrotalcites were synthesized with magnetic substrates and hydrotalcite-like compounds by using hydrothermal. The emphasis is that magnetic hytrotalcite with lamellar structure have been designed and prepared for more easily and high efficiency reclaim of the catalysts. The influence of calcined temperatures on the structure, purity, crystallinity, and magnetic properties of the materials was studied at range of set temperature, pH, crystal temprature and the amount of magnetic component. The presented samples were characterized in detail by XRD, IR, TG-DSC, TEM, HRTEM, SEM and VSM techniques. The purpose of all works is to obtain the optimum condition.The results showed that typical layered structures of hydrotalcite are not affected by introducing a certain range of magnetic substrates during the synthetic process. Characteristic diffraction peaks of magnetic hydrotalcite are observed in the XRD patterns. The magnetic hydrotalcites have not only regular fabric but also a good magnetism performance if the intake of magnetic substrates is 10 mL. HRTEM and FFT images demonstrate the formation of well-crystallized and in good situation of growth of crystal. N₂ adsorption/desorption studies reveal that magnetic hydrotalcites are porous material with higher value of S_BET and smaller value of d_p, the .S_BET of magnetic Zn-Ni-Al hydrotalcite calcined at 400℃is 170 m²/g and the value of d_p is 6.007 nm. The result of VSM approved it has better magnetism nature. The results indicate that Zn-Ni-Al hydrotalcite can be used as the carrier of catalyst.In order to confirm the specific property "memory effect" of hytrotalcite-like compounds, the collapse structure recovery experiments were done in the same experiment condition as synthesized hydrotalcite-like compounds. Experimental result indicate that laminated structure can be restored if precursor be calcined at lower temperarure, this phenomenon should be owed to the appearance of complex oxide in this case. On the contrary, laminated structure be restored is impossible because the sample converted to spinel under higher temperature.更多还原