基于锌帽型钼磷酸盐配位聚合物的合成及电化学性质研究
发布时间：2018-11-24 16:02
【摘要】：多金属氧酸盐作为一类拥有多样结构和优异物理化学性质的一类纳米簇,由于其高的电荷密度,氧化还原性能以及通过修饰可实现功能化等特点,在医学,生物学,磁性,材料科学和催化等领域展现出有前景的应用价值。目前,多酸的修饰化成为实现多酸功能化的主要途径,其中帽式多酸的研究一直是极具吸引力的课题。基于锌帽的多金属氧酸盐的研究还不太多见,关于其性质研究的报道就更少见。因此本论文将目光聚集在基于锌帽的磷钼酸盐的结构和性能研究,在本文中首次实现了锌帽取代的多酸与线形刚性双功能有机配体直接相连,同时Zn-ε-Keggin单元作为典型的可变价金属簇显示出可逆的氧化还原活性,因此多酸基配位聚合物可应用于锂离子电池以及电解水产氢中。在本论文中采用常规水热的合成方法,通过调节PH值,与不同的配体实现了对锌帽型磷钼酸盐的修饰。两例具有金刚石拓扑的结构新颖、同构的多酸基配位聚合物被成功合成。通过单晶X-射线衍射、IR、TG以及元素分析等表征手段研究了化合物的组成、结构等。(TBA)3 [PMoV8MoVI4O38(OH)2Zn4(IN)2](NENU-506)(TBA)3 [PMoV8MoVI4O38(OH)2Zn4(PBA)2]·H2O(NENU-507)不同于传统的多酸基配位聚合物,NENU-506和NENU-507展现出很好的热稳定性和化学稳定性。二者可以在很宽的PH范围(2-12)内稳定存在,证明了其对酸/碱水溶液的极好耐受性。在室温下将二者在常规有机溶剂浸泡3天后,其PXRD显示二者仍保持着晶体框架,证明其在常规溶剂中也具有很好的稳定性。鉴于NENU-507优异的化学和热稳定性,将其直接用作锂离子电池的负极材料。研究表明,在锂化/脱锂循环期间,NENU-507能够保持其三维刚性结构。当电流密度为100 mA g-1时,NENU-507电极在100个循环后显示出的可逆容量为640 mA h g-1。在相似的条件,利用四帽锌取代的磷钼酸与含羧酸的有机配体形成了化合物NENU-508,其分子式为:(TBA)5[PMoV8MoVI4O38(OH)2Zn4(NTB)Cl];与含氮的有机配体形成了化合物NENU-509,其分子式:(TBA)[PMoV8MoVI4O38(OH)2Zn4(BDMPX)2]·5H2O,并且对二者进行了红外、XRPD、热重表征,他们具有较好的酸碱稳定性。由于POM单元的氧化还原活性以及MOF的孔隙,使得其有望替代贵金属催化剂,应用于电解水产氢的研究。
[Abstract]:Polyoxometalates are a kind of nanoclusters with various structures and excellent physical and chemical properties. Due to their high charge density, redox properties and functionalization through modification, polyoxometalates are widely used in medicine, biology, magnetism, etc. Materials science and catalysis show promising application value. At present, the modification of polyacids is the main way to realize the functionalization of polyacids. Studies on zinc cap-based polyoxometalates have not been seen much, and reports on their properties are even rarer. Therefore, the structure and properties of phosphomolybdate based on zinc cap are studied in this paper. In this paper, the polyacid replaced by zinc cap is directly connected with linear rigid bifunctional organic ligands for the first time. At the same time, the Zn- 蔚-Keggin unit shows reversible redox activity as a typical variable valence metal cluster, so polyacid-base coordination polymers can be used in lithium ion batteries and electrolytic aquatic hydrogen. In this paper, the zinc cap phosphomolybdate was modified with different ligands by adjusting the PH value by the conventional hydrothermal synthesis method. Two examples with diamond topology have been successfully synthesized, with novel structure and isomorphic polyacid-group coordination polymer. The composition of the compounds was studied by means of X-ray diffraction, IR,TG and elemental analysis. The structure of. (TBA) _ 3 [PMoV8MoVI4O38 (OH) 2Zn4 (IN) _ 2] (NENU-506) (TBA) _ 3 [PMoV8MoVI4O38 (OH) 2Zn4 (PBA) _ 2] H _ 2O (NENU-507) is different from that of traditional polyacid-group coordination polymers. NENU-506 and NENU-507 show good thermal and chemical stability. They can exist stably in a wide range of PH (2-12), which proves their excellent tolerance to acid / alkaline water solution. After immersing them in conventional organic solvents at room temperature for 3 days, their PXRD showed that they still maintained the crystal frame, which proved that they also had good stability in conventional solvents. Due to its excellent chemical and thermal stability, NENU-507 is directly used as anode material for lithium ion batteries. The results show that NENU-507 can maintain its three dimensional rigid structure during lithiation / delithium cycle. When the current density is 100 mA g ~ (-1), the reversible capacity of the NENU-507 electrode is 640 mA h ~ (-1) after 100 cycles. Under similar conditions, the compound NENU-508, was formed by using the organic ligands containing carboxylic acids and substituted phosphomolybdic acid. The molecular formula of the compound is: (TBA) 5 [PMoV8MoVI4O38 (OH) 2Zn4 (NTB) Cl]. The compound NENU-509, was formed with nitrogen-containing organic ligands and its molecular formula: (TBA) [PMoV8MoVI4O38 (OH) 2Zn4 (BDMPX) _ 2] _ 5H _ 2O was obtained. They were characterized by IR and XRPD, thermogravimetry. They have good acid-base stability. Because of the redox activity of POM unit and the pore of MOF, it is expected to replace the noble metal catalyst and be used in the study of electrolytic hydrogen in aquatic products.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4
本文编号：2354307
[Abstract]:Polyoxometalates are a kind of nanoclusters with various structures and excellent physical and chemical properties. Due to their high charge density, redox properties and functionalization through modification, polyoxometalates are widely used in medicine, biology, magnetism, etc. Materials science and catalysis show promising application value. At present, the modification of polyacids is the main way to realize the functionalization of polyacids. Studies on zinc cap-based polyoxometalates have not been seen much, and reports on their properties are even rarer. Therefore, the structure and properties of phosphomolybdate based on zinc cap are studied in this paper. In this paper, the polyacid replaced by zinc cap is directly connected with linear rigid bifunctional organic ligands for the first time. At the same time, the Zn- 蔚-Keggin unit shows reversible redox activity as a typical variable valence metal cluster, so polyacid-base coordination polymers can be used in lithium ion batteries and electrolytic aquatic hydrogen. In this paper, the zinc cap phosphomolybdate was modified with different ligands by adjusting the PH value by the conventional hydrothermal synthesis method. Two examples with diamond topology have been successfully synthesized, with novel structure and isomorphic polyacid-group coordination polymer. The composition of the compounds was studied by means of X-ray diffraction, IR,TG and elemental analysis. The structure of. (TBA) _ 3 [PMoV8MoVI4O38 (OH) 2Zn4 (IN) _ 2] (NENU-506) (TBA) _ 3 [PMoV8MoVI4O38 (OH) 2Zn4 (PBA) _ 2] H _ 2O (NENU-507) is different from that of traditional polyacid-group coordination polymers. NENU-506 and NENU-507 show good thermal and chemical stability. They can exist stably in a wide range of PH (2-12), which proves their excellent tolerance to acid / alkaline water solution. After immersing them in conventional organic solvents at room temperature for 3 days, their PXRD showed that they still maintained the crystal frame, which proved that they also had good stability in conventional solvents. Due to its excellent chemical and thermal stability, NENU-507 is directly used as anode material for lithium ion batteries. The results show that NENU-507 can maintain its three dimensional rigid structure during lithiation / delithium cycle. When the current density is 100 mA g ~ (-1), the reversible capacity of the NENU-507 electrode is 640 mA h ~ (-1) after 100 cycles. Under similar conditions, the compound NENU-508, was formed by using the organic ligands containing carboxylic acids and substituted phosphomolybdic acid. The molecular formula of the compound is: (TBA) 5 [PMoV8MoVI4O38 (OH) 2Zn4 (NTB) Cl]. The compound NENU-509, was formed with nitrogen-containing organic ligands and its molecular formula: (TBA) [PMoV8MoVI4O38 (OH) 2Zn4 (BDMPX) _ 2] _ 5H _ 2O was obtained. They were characterized by IR and XRPD, thermogravimetry. They have good acid-base stability. Because of the redox activity of POM unit and the pore of MOF, it is expected to replace the noble metal catalyst and be used in the study of electrolytic hydrogen in aquatic products.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4
【参考文献】
相关期刊论文 前1条
1 刘娅;徐峰;;世界氢能与氢经济的发展概况及不同认识[J];世界科技研究与发展;2006年01期
，本文编号：2354307
本文链接：https://www.wllwen.com/kejilunwen/huaxue/2354307.html
教材专著
