多酸基金属有机配位网络制备及功能性研究
发布时间：2018-12-10 21:57
【摘要】：近年来,有关多酸基金属有机配位网络的研究已经成为无机化学领域一个热点问题。将具有独特性能的多酸基元与结构丰富的金属有机配位网络相结合,可以获得一系列具有多重功能特性的杂化材料。迄今为止,这些杂化材料已经在酸催化、氧化催化、光催化、电催化等方面展现出潜在的应用前景。然而,与多酸基金属有机配位网络制备和合成的数量相比,对其功能特性的开发却仅仅只占了一小部分。因此,制备具有新型功能特性的多酸基金属-有机配位网络,拓展其新的应用领域已成为当前备受关注的课题。基于此,本论文利用水热合成方法设计合成了两类新型多酸基金属有机配位网络,并且开发其在电催化析氢和贵金属附载两个领域的功能特性。1、我们以α-Keggin型{PMo_(12)}多酸为模板,通过与过渡金属Zn~(2+)以及两种刚性咪唑桥连配体(bimbp/bimb)反应,成功获得了两例多酸嵌入型金属有机配位网络：[Zn(bimbp)_2]_3[PMo_(12)O_(40)]_2·2H_2O (1)[Bu_4N][Zn_3(bimb)_4Cl(MoO_4)][PMo~ⅤMo_(11)~(Ⅵ)O_(40)]·4H_2O (2)(bimbp= 4,4'-bis(imidazolyl)biphenyl, bimb=1,4-bis(1-imidazolyl)benzene)对化合物1-2进行了红外、热重、元素分析、X-射线粉末衍射和X-射线单晶结构解析,明确了晶体结构。之后,将化合物1-2在管式炉中氮气保护条件下进行800℃高温煅烧；并在冷却后进行酸蚀刻处理,获得了能够替代贵金属铂的新型析氢反应(HER)电催化剂：MoC_x@C-1和MoC_x-2。Mo@C-1为氮掺杂类石墨化碳包覆的碳化钼纳米粒子,MoC_x-2为超细碳化钼纳米粒子；二者均在酸性介质中展现出了卓越的HER性能。其中,MoC_x@C-1具有比较正起始电位,在电流密度10 mA·cm~(-2)条件下的过电位为79 mV,接近该条件下的商用催化剂Pt/C (20%); MoC_x@C-1还具有低的塔菲尔斜率(56mV-dec~(-1)),高的交换电流密度(0.27 mA·cm~(-2)),以及卓越的循环稳定性。2、我们通过使用ε-Keggin型多酸建筑单元和四种刚性咪唑桥连配体(bimbp/bimb/bimbp/timb)在水热条件下自组装,成功构筑了四例新颖的还原型多酸基金属有机配位网络：H[(Hbimb)_2(bimb) {Zn_4PMO_8~ⅤMo_4~(Ⅵ)O_(40)}]·6H_2O (3),[Zn(Hbimbp)(bimbp)_3{Zn_4PMo~ⅤgMo_4~(Ⅵ)O_(40)}]·DMF·3.5H_2O (4),H[Zn_2(timb)_2(bimba)_2Cl2]{Zn_4PMO_8~ⅤMo_4~(Ⅵ)O_(40)}]·7H_2O (5),imb)_2] [PMO_8~ⅤMo_4~(Ⅵ)O_(40)]·12H_2O(6)。(timb=1,3,5-tris(1-imidazolyl)benzene, bimba= 3,5-bis(1-imidazolyl)benzenamine)通过结构表征证实,化合物3是由1D锯齿链通过分子间的氢键作用拓展形成的3D超分子结构。化合物4是二维曲面,化合物5是手性配位网络,化合物6为四重互穿型金刚石网络。基于网络结构中多酸潜在的还原性能,将化合物3-5用于担载贵金属纳米粒子)(NPs)的研究,得到了Ag NPs/化合物3-5复合材料。发现其在对硝基苯酚的还原上表现出极高的催化活性。
[Abstract]:In recent years, the study of polyacid-based organometallic coordination networks has become a hot issue in inorganic chemistry. A series of hybrid materials with multi-functional properties can be obtained by combining the unique polyacid units with the metal-organic coordination network with rich structure. So far, these hybrid materials have shown potential applications in acid catalysis, oxidation catalysis, photocatalysis, electrocatalysis and so on. However, compared with the preparation and synthesis of polyacid-based organometallic coordination networks, the development of their functional properties is only a small part. Therefore, the preparation of polyacid-base metal-organic coordination networks with new functional characteristics and the expansion of their new application fields have become a subject of great concern. Based on this, two kinds of novel polyacid-base organometallic coordination networks were designed and synthesized by hydrothermal synthesis method, and their functional characteristics in the fields of electrocatalytic hydrogen evolution and noble metal loading were developed. 伪-Keggin {PMo_ (12)} polyacid was used as a template to react with transition metal Zn~ (2) and two rigid imidazole bridged ligand (bimbp/bimb). Two polyacid-embedded organometallic coordination networks have been successfully obtained: [Zn (bimbp) _ 2] _ 3 [PMo_ (12) O _ (40)] _ 2 2H_2O (1) [Bu_4N] [Zn_3 (bimb) _ 4Cl (MoO_4)] [PMo~ 鈪，
本文编号：2371267
[Abstract]:In recent years, the study of polyacid-based organometallic coordination networks has become a hot issue in inorganic chemistry. A series of hybrid materials with multi-functional properties can be obtained by combining the unique polyacid units with the metal-organic coordination network with rich structure. So far, these hybrid materials have shown potential applications in acid catalysis, oxidation catalysis, photocatalysis, electrocatalysis and so on. However, compared with the preparation and synthesis of polyacid-based organometallic coordination networks, the development of their functional properties is only a small part. Therefore, the preparation of polyacid-base metal-organic coordination networks with new functional characteristics and the expansion of their new application fields have become a subject of great concern. Based on this, two kinds of novel polyacid-base organometallic coordination networks were designed and synthesized by hydrothermal synthesis method, and their functional characteristics in the fields of electrocatalytic hydrogen evolution and noble metal loading were developed. 伪-Keggin {PMo_ (12)} polyacid was used as a template to react with transition metal Zn~ (2) and two rigid imidazole bridged ligand (bimbp/bimb). Two polyacid-embedded organometallic coordination networks have been successfully obtained: [Zn (bimbp) _ 2] _ 3 [PMo_ (12) O _ (40)] _ 2 2H_2O (1) [Bu_4N] [Zn_3 (bimb) _ 4Cl (MoO_4)] [PMo~ 鈪，
本文编号：2371267
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