基于CO2与胺/H2的N-甲酰(基)化反应磁性MOFs催化剂构建及CUS催化作用机制

In highly active catalysts, CO2 with amine/H2 can be converted into more valuable products of the N-formamide and the N-methylamine through the N-formylation (N-methylation) reaction. When using the homogeneous catalyst, the reaction conditions are milder but the separation of the catalyst and the reactant was difficult. In this project a new method for construction the magnetic core-shell MOFs catalyst was proposed. This is that, firstly, the MOFs shell layer with coordinative unsaturated sites (CUS) was in situ synthesized and coated on the surface of superparamagnetic Fe3O4 core with protected layer and the magnetic MOFs@Fe3O4 microsphere particles were prepared. Secondly, the catalytic activity components, such as Ru, Au, and Pd, are assembled into the MOFs shell of magnetic MOFs@Fe3O4 particles. Finally, the magnetic MOFs catalysts, named the catalytic activity components/MOFs@Fe3O4 are prepared. At the same time, the performance of the magnetic MOFs catalysts for the CO2 with amine/H2 to form N-formamide and the N-methylamine in the liquid-solid catalytic reactor will be evaluated. The relationship of the catalytic active components and the structure of MOFs, the catalytic mechanism of CUS coordination active CO2, and the recycling properties of the magnetic MOFs catalysts will be adequately investigated. Actualized this project, the new technology of preparation the magnetic MOFs catalysts and the catalysis process of the CO2 with amine/H2 to form N-formamide and the N-methylamine will be formed. This project has an important scientific significance to understand the role of magnetic MOFs catalysts for the N-formylation and N-methylation reaction of the CO2 with amine/H2 and the catalytic mechanism of CUS coordination active CO2 over the magnetic MOFs catalysts. There is a bright future application for the CO2 with amine/H2 to form N-formamide and the N-methylamine catalysis process.

在催化剂作用下CO2与胺/H2反应可以生成高附加值N-甲酰(基)胺产物。均相催化剂的反应条件温和，但催化剂和反应物的分离比较困难。本项目提出一种新的磁性核MOFs催化剂制备方法，即在磁性Fe3O4颗粒表面原位合成一层具有配位不饱和位(CUS)的MOFs材料，制成MOFs@Fe3O4磁性微球，再将Ru、Au、Pd等组装在磁性MOFs@Fe3O4中，制备出“催化活性组分/MOFs@Fe3O4核”磁性催化剂。然后在液-固反应器中评价CO2与胺/H2的N-甲酰(基)化性能，深入研究催化剂的制备、结构与性能关系和CUS活化CO2的机制，形成磁性MOFs催化剂制备新技术和CO2与胺/H2反应合成N-甲酰(基) 胺新工艺。项目实施对认识磁性MOFs催化剂对CO2与胺/H2的N-甲酰(基)化反应性能、CUS活化CO2的机制有重要的科学意义，对实现CO2与胺/H2生成N-甲酰(基)胺新工艺有重要的应用价值。

在催化剂作用下CO2与胺/H2反应可以生成高附加值N-甲酰(基)胺产物。本项目研制了（1）具有配位不饱和位(CUS)的MIL-101(Cr)、MOF-808(Zr)、UiO-66(Hf)、UiO-66(Zr)、MIL-100(Fe)、MIL-100(Cr)、NH2-MIL-101(Al)等MOFs材料组装金属催化活性组分的催化剂；（2）筛选的具有CUS的MOFs材料组装Au、Ru、Pd、Pt单金属和Au与M2（Pd、Pt、Ni、Cu、Ru、Co、Ce）双金属催化活性组分的催化剂；（3）优化出具有CUS 的MOFs材料组装优异催化活性组分的催化剂；（4）在超顺磁性SiO2@Fe3O4微球表面原位生长具有CUS的MIL-101(Cr)壳层组装Au催化活性组分的磁性Au/MIL-101(Cr)@SiO2@Fe3O4双功能催化剂。采用XRD、FT-IR、SEM、HRTEM、N2 吸附-脱附、XPS、NH3-TPD和VSM等手段对催化剂结构、形貌特征、磁性等进行了详细表征，评价了催化剂的CO2与胺/H2的N-甲酰(基)化反应性能，深入研究了催化剂制备条件和反应工艺条件与催化反应性能的关系，考察了催化剂对脂肪胺、杂环胺、环烷胺和芳香胺等不同种类胺与CO2/H2的N-甲酰（基）化反应性能和磁性催化剂使用后外磁场回收和重复使用性能，从而确定了CO2与胺/H2进行N-甲基化和N-甲酰化反应过程的中间物种、加氢活性中心和酰基化活性中心，获得了催化剂的CUS位点活化CO2进而转化为N-甲酰(基)的机制和对CO2与胺/H2的N-甲酰(基)化的反应机理，形成了具有CUS磁性MOFs催化剂制备新技术和CO2与胺/H2反应合成N-甲酰(基) 胺新工艺。研究工作对认识MOFs催化剂的CUS活化CO2进而转化为N-甲酰(基)的机制和CO2与胺/H2的N-甲酰(基)化反应机理有重要的科学意义和应用价值。