【作者】 罗勇；

【导师】 贺庆林；

【作者基本信息】 东北师范大学 ， 无机化学， 2009， 硕士

【摘要】 在本论文研究中,通过Ni²⁺、Cu²⁺、Co²⁺、Mn²⁺、Cr³⁺及Fe³⁺等过渡金属离子与EDTA、草酸、丙二酸及CN^-等多齿或单齿配体配位,合成了相应的过渡金属配合物阴离子,利用共沉淀及离子交换插层组装方法,制备了过渡金属配合物阴离子柱撑水滑石Mg₃Al-LDHs/[MY](M为Ni²⁺、CU²⁺、Co²⁺、Mn²⁺、Cr³⁺,Y为EDTA)、Ni₃Fe-LDH/[CoY]、Ni₃Al-LDH/[CoY]及Ni₂Al-LDH/[Cr（C₂O₄）₃]、Ni₂Al-LDH/[Cr（C₃H₂O₄）₃]、Ni₂Al-LDH/[Fe（C₂O₄）₃]、Ni₂Al-LDH/[Fe（CN）₆]。通过XRD、FT-IR、ICP、TG-DTA等对它们的组成和结构进行了分析表征,研究了反应条件对插层组装的影响。以肉桂醛的过氧化氢氧化反应为探针反应,考察了过渡金属配合物阴离子柱撑水滑石插层化合物的氧化催化性能。研究结果表明,利用共沉淀插层组装方法制备Mg₃Al-LDHs/[MY]的适宜条件为:Mg/Al配比为3.00、共沉淀酸度pH=9.0、晶化温度为90℃,晶化时间为24 h。利用离子交换法制备过渡金属配合物阴离子-Ni₂Al-LDHs的适宜插层组装条件为:以Ni₂Al-LDH/NO₃为前躯体,控制体系酸度pH=6.5、85-90℃下交换48h。粉末X-射线衍射及元素分析表明,在上述插层组装条件下,得到的过渡金属配合物阴离子柱撑水滑石层状结构规则有序,具有典型的水滑石结构特征,且组成符合类水滑石组成通式。FT-IR分析表明,LDHs层间过渡金属配合物阴离子保持其原有结构不变。TG热分析表明,所制备的层柱复合体具有较高的热稳定性,层柱结构完全破坏的温度一般在400℃以上。通过考察过渡金属配合物阴离子尺寸和LDHs层间孔道高度,结合主客体间的相互作用,推断了LDHs层间配合物阴离子的排布方式。在Mg₃Al-LDHs/[MY]层间,过渡金属-EDTA配合物阴离子采取以其最小维度垂直于层板、双分子层叠加的方式在层间排布;在Ni₂Al-LDH/[Cr（C₂O₄）₃]、Ni₂Al-LDH/[Cr（C₃H₂O₄）₃]、Ni₂Al-LDH/[Fe（C₂O₄）₃]及Ni₂Al-LDH/[Fe（CN）₆]层间,客体阴离子均采取以其C3轴垂直于层板的、单层形式在层间排布。这样的排布方式使主客体间的静电作用及氢键作用最大,插层化合物结构最为稳定。在体积匹配、电性匹配和空间构型匹配的前提下,主客体间的相互作用是影响层间配阴离子排布形式的关键因素。柱撑水滑石化合物对过氧化氢氧化肉桂醛反应具有明显的催化作用,其催化效果来源于层板和层间阴离子的双重作用,层板的组成及层间阴离子的种类对催化性能有很大影响,当层板元素为过渡金属Ni和Fe、层间阴离子为[CoY]^2-时,催化活性最好。更多还原

【Abstract】 In this thesis anionic EDTA,oxalate,malonate,cyanide coordination compound of transition metal ions Ni²⁺,Cu²⁺,Co²⁺,Mn²⁺,Cr³⁺,are bridged through electrostatic and H-bonding interactions into Mg₃Al-LDHs and Ni₂Al-LDHs on the basis of the their anion exchange property.Mg₃Al-LDHs/[MY](M=Ni²⁺,Cu²⁺,Co²⁺,Mn²⁺,Cr³⁺, Y=EDTA),Ni₃Fe-LDH/[CoY]and Ni₃Al-LDH/[CoY]were synthsized by co-precipitation method.Intercalation compounds of Ni₂Al-LDHs,with[Cr（C₂O₄）₃]^3-, [Cr（C₃H₂O₄）₃]^3-,[Fe（C₂O₄）₃]^3- and[Fe（CN）₆]^3- complexes were obtained via intercalation and assembly processes.The composition,structure and property of the products thereby obtained have been studied by using XRD,FT-IR,ICP and TG-DTA. Catalytic activity for the H₂O₂ oxidation of cinnamaldehyde of the composite materials was also investigated.The results indicated that,all the obtained composites had better organized stacking arrangement by controlling experimental conditions:when the Mg/Al ratio was 3.00,co-precipitation was under pH=9.0,aging at 90℃24 h;when the Ni/Al ratio was 2.00,ion-exchange processes was under pH=6.5 and 85-90℃or ambient temperature for 48 h.XRD and vibrational spectroscopy studies confirmed that the integrity of the transition metal complexes was preserved upon incorporation into LDHs.TG analysis showed that all the composite materials obtained had well thermal stability,the layer structure was completely destoried above 400℃.The orientation and arrangement of the transition metal complexes within the interlayer had also been investigated.In the case of Mg₃Al- LDHs/[MY]the interlayer separation indicated that the guest species were arranged in a bilayer with the minimal dimension perpendicular to the host layers;In Ni₂Al-LDH/[Cr（C₂O₄）₃]、Ni₂Al-LDH /[Cr（C₃H₂O₄）₃]、Ni₂Al-LDH/[Fe（C₂O₄）₃]、Ni₂Al-LDH/[Fe（CN）₆]the guest species were all arranged in a monolayer with their C3 axises perpendicular to the host layers.These orientations can maximize the electrostatic force and hydrogen bonds between the host and guest species.The host materials can meet the matching of volume,electricity and construction of the guest species,which were main factors in affecting the orientation and arrangement of the guest species.The catalytic activities of the composite materials were extensively studied.It was observed that the catalytic activities of the composite materials LDHs mainly attributed to the synergetic effect between transition metal complexes and LDHs.The most optimal catalytic performance came from the LDHs which the[CoY]^2- anion was intercalated into the interlayer space of Ni₃Fe-LDHs.更多还原