环境友好型多金属氧簇的结构设计与催化特性

By virtue of their outstanding acidity and oxidability, polyoxometalates (POMs) as a class of environment-friendly catalysts, have possessed critical applications in petrochemical, material, environmental, energy, and other fields. Some of these applications have also been successfully scaled-up and industrialized over the past several decades and POMs chemistry in turn has became an important cross-disciplinary research area. Herein this project focuses on three aspects of the innovative research: 1) structure design strategy and characterization methodology of novel POMs; 2) design and assembly of the ordered porous structures of POMs, and 3) catalytic properties of POMs, i.e. activation of the C-H bonds of aromatic hydrocarbon, oxidative desulfurization of petroleum, and production of hydrogen and/or oxygen by photocatalytic water splitting, etc. Specifically the new methods will be developed to design, assemble and characterize the structures of POMs while the underline principles will be investigated between the performance of photocatalytic water splitting and the structure-activity of these novel POMs. Further the reaction mechanism of C-H bond breaking and C-C bond formation will be studied and elaborated. Also the technical bottlenecks in precipitation, recycling and reuse of POMs catalysts will be broken and new approaches will be established to immobilize such POMs catalysts into metal-organic frameworks (MOFs). It is aimed at providing the scientific basis and technological support for using these environmental-friendly POMs catalysts in chemical and petrochemical industries. It is also of great scientific and practical importance to enrich and develop POMs chemistry and to explore the possibilities of POMs in catalytic field.

多金属氧酸盐(POMs)是一类具有酸性和氧化性的环境友好型催化剂，在石油化工、材料、环境及能源等领域具有重要应用，国际上已有若干个POMs催化的反应实现了产业化。目前POMs化学已成为多学科交叉研究的热点领域。本项目聚焦新型POMs的结构设计、表征方法和催化特性，开展有序孔结构POMs的结构设计组装策略、催化活化芳香烃C-H键、石油氧化脱硫特性及光催化分解水制氢和氧的性能三个方面内容的创新研究；建立POMs的结构设计组装与表征新方法；发现新型POMs光催化分解水的特性与构效关系规律，阐明POMs催化断裂C-H键及形成C-C键的作用机理；突破固体POMs催化剂的溶出、回收和再利用技术瓶颈，开辟MOFs担载POMs催化剂的固载化新途径，为环境友好型POMs催化剂在化工和石油化工等领域中的应用提供科学依据和技术支撑。该项目对于丰富和发展POMs化学及其拓展催化应用领域具有重要科学意义和应用价值。

多金属氧酸盐(POMs)是一类具有酸性和氧化性的环境友好型催化剂，在石油化工、材料、环境及能源等领域具有重要应用，国际上已有若干个POMs催化的反应实现了产业化。目前POMs化学已成为多学科交叉研究的热点领域。本项目聚焦新型POMs的结构设计、表征方法和催化特性，开展新型POMs的结构设计策略、催化醇分子需氧氧化、活化芳香烃C-H键及石油氧化脱硫特性等方面内容的创新研究，主要取得如下成果：1、设计合成了有机官能化的多钒氧簇和贵金属配合物修饰的多金属氧簇，将它们应用到醇分子的需氧氧化和C-H键活化反应中，显示出优异的催化性能。对其催化机理进行了深入研究，得到了高活性的中间体。 2、探索了POM@MOFs材料的纳米化新途径，得到两亲性、多孔性及双酸活性位点协同作用的新型催化材料，有效地实现了多酸催化剂在油相中的均匀稳定分散，在石油深度脱硫反应中显示出优异的催化活性。进一步设计合成了晶面选择性酸催化剂POM@MOFs，突破了传统MOFs催化剂的孔道尺寸限制效应，首次实现了对亚微米尺度的POM@MOFs材料的晶面调控，深入探索了不同形貌亚微米晶的形成机理。3、以缺位多钨酸盐为前驱体将铌（钽）引入到酸性及中性反应体系中，得到多种新型结构的Nb(Ta)/W混配型多酸簇，深入研究了Nb(Ta)/W混配型多酸在溶液中组装规律和衍生化反应条件。另外，将S作为中心杂原子或将钴离子配合物引入到多铌氧簇体系中，得到了5中结构新颖的多铌氧簇。4、设计合成了Ti/W混配型多酸银盐，获得了具有较高产氧及降解染料活性的光催化剂。深入研究了银及钛的引入对Keggin型钨磷酸光吸收性质的影响。5、用电喷雾质谱对夹心型多钨氧簇的溶液行为进行表征，研究了稀土修饰的多钨氧簇在溶液中的自组装机理。