量热法研究配体改性对FeCo双金属氰化物结构及其催化苯乙烯环氧化反应的影响

Although microcalorimetry is an effective way to study the properties of catalysts and catalytic mechanism in the homogeneous phase, the corresponding researches on the nanoparticle catalysts have rarely been reported. Ligand-binding is a very important method to improve the property of catalyst, so the studies on the modification mechanism of ligand will be crucial for the future design of novel catalyst materials. In this proposal, FeCo Double metal cyanide(DMC) will be modified by ligands with different structures and willl be utilized to catalyze the epoxidation of styrene. The isothermal titration calorimetry (ITC) will be used to investigate the effect of ligands on the synthesis process of FeCoDMC, and the absorption details of oxidizer on the FeCoDMC surfaces. To further clarify the coordination process, the slab and cluster models of FeCoDMC will be established based on Density functional theory to investigate the effect of the ligand on the structure of DMC and catalysis process of epoxidation of styrene. In combination with the thermodynamic, quantum chemistry calculation and catalytic activity studies, the effect of different categories and structures of ligands on the structure and activity of catalyst and catalytic mechanism will be thoroughly discussed. The results will elucidate the catalytic mechanism of double metal cyanide, the relationship of the structure-property and provide valuable theoretical support to experiments, which will be crucial for the future design of novel catalyst materials.

微量热法是探究催化剂性质和催化反应机理的有效方法，但在固体催化剂的研究中应用得还非常少。配体改性是提高催化剂性能的重要手段,其内在机理的研究对设计新型高效的催化剂具有理论指导意义。我们拟用不同结构的配体分别改性FeCo双金属氰化物(DMC)催化剂，选择能够提高或降低DMC催化苯乙烯环氧化反应效率的配体，再以等温滴定量热为主要手段，研究配体改性对FeCoDMC催化剂的合成，以及催化剂吸附氧化剂的影响；同时结合Materials Studio和Gaussian软件，应用密度泛函理论建立FeCoDMC的晶面模型，研究配体改性对催化剂微观结构及催化苯乙烯环氧化的机理、反应能垒的影响；结合热力学、量化计算以及催化实验的研究结果，深入探讨DMC催化剂结构和性能的关系，为如何进一步提高该类催化剂的催化活性提供依据，具有重要的科学意义和实际应用价值。

为了深入探究改性提高催化剂性能的内在原因，本项目将催化、微量热以及量化计算的研究结果相结合，探讨不同的改性方法对催化剂结构、性质和催化反应机理的影响。我们利用碱金属、第三种金属以及醇类、酰胺类等不同方法分别改性FeCo双金属氰化物(DMC)，研究了不同改性方法对FeCo双金属氰化物催化苯乙烯环氧化反应性能的影响；然后通过等温滴定量热仪研究不同改性方法对FeCo双金属氰化物合成过程热力学性质的影响，并对比改性前后催化剂吸附过氧化叔丁基氧化剂过程的热动力学；同时应用密度泛函理论建立FeCo DMC的晶面模型，研究配体改性对催化剂催化苯乙烯环氧化的机理、反应能垒的影响。项目按计划顺利完成。