缺陷MOFs限阈的活性纳米金属氧化物燃烧催化剂的制备及催化效能研究

实现催化剂活性位点的最大暴露及与组份间的充分接触是研制高效燃烧催化剂的核心。本项目通过晶体缺陷工程策略，以不同热稳定性的芳香羧酸配体，对标绿色燃烧催化剂氧化物，基于小分子酸的配位竞争制备缺陷MOFs燃烧催化剂。缺陷位、高度暴露的金属位点与纳米活性氧化物的协同催化赋予燃烧催化剂足够的催化效能。基于X-射线衍射分析、微量热、TG-DTG-DSC技术，确定缺陷MOFs的形成机理、结构与热稳定性关联；选择热解条件去除结构中薄弱的化学键组份，生成的MO均一分布在MOFs扩大的孔道内形成新型燃烧催化剂。进行配方试验评价复合材料在双基推进剂中的燃烧效能，建立热解条件-结构-催化效能的关系，筛选得到高活性催化剂。项目的创新在于缺陷结构赋予催化活性提高的同时，又使MOFs结构中化学键强度明确分级，为热解制备高催化活性MO@HP-MOFs提供了技术支持，研究工作以全新的策略实现高活性燃烧催化剂的构筑。

It is the key to achieve exposure of active sites as possible and full contact with other components for development of high efficiency combustion catalysts. In this project, based on crystal defect engineering strategy through coordination competition of small molecular acids, the carboxylic acid ligands with different thermostability are selected to coordinate to metal ions, to prepare defected MOFs combustion catalysts. The synergistic catalysis of defect sites, highly exposed metal sites and nano active oxides would endow combustion catalysts with sufficient catalytic activity and efficiency. Dependent on X-ray diffraction analysis, microcalorimetry, TG-DTG-DSC techniques, the correlation among the formation mechanism, structure and thermostability for the detected MOFs would be determined. Under the optimized pyrolysis conditions, the components with weak chemical bond in the MOFs would be removed to produce novel combustion catalysis MO@HP-MOFs (HP-MOFs，hierarchically porous MOFs) which nano-oxides formed are highly uniform-distributed in the expanded pore channels of MOFs. The combustion efficiency of composite materials in the double base propellant can be evaluated by the formula tests. The relationship among thermal decomposition conditions, structure and the combustion efficiency would be established and the combustion catalysts with high-activity be filtered. The innovation in the project highlights that the defective structure is benefit for the improvement for the high catalysis activity when the chemical bond strength in the MOFs is clearly graded, providing technical support for the preparation of MO@HP-MOFs with high catalytic activity by pyrolysis. The research would accomplish the construction of high activity combustion catalysts with the proposed strategy.