费托合成联产高碳醇高分散负载型Cu-Fe双金属纳米催化剂的可控制备及反应机理

Higher alcohols is a basic raw material for several final chemical engineering products like surfactant, detergent, plasticizer, etc. It has higher economic value than other products like hydrocarbons and light alcohols although it is only the by-product in Fischer-Tropsch synthesis. Liquid phase reduction method is adopted in the study for the preparation of the supported Cu-Fe bimetal nanoparticle catalyst with high dispersion for Fischer-Tropsch synthesis to improve the selectivity of higher alcohols. The preparation method and conditions for the supported Cu-Fe bimetal nanoparticle catalyst were achieved from the research of regulating the supporters, reduction temperature, dispersant, reductant and complexing agent, and the structure-function relationship of preparation method, microstructure of catalyst, particle size and dispersity of active metal, and the reaction performance is established by combing the catalyst characterization techniques. The reaction mechanism of higher alcohols synthesis during the Fischer-Tropsch reaction process is studied and cleared by combining the in-situ characterization and analysis techniques and DFT calculation. The lumped reaction kinetics of Fischer-Tropsch synthesis containing higher alcohols is developed based on the achieved reaction mechanism. The research achievement is beneficial to understand the mechanism of Fischer-Tropsch synthesis and higher alcohols production, and can also be used to guide the optimal design and development of nano-catalyst for Fischer-Tropsch synthesis, and provide theory support for the scaling-up of catalysts and reactors.

高碳醇是合成表面活性剂、洗涤剂和增塑剂等精细化工产品的主要原料，相对于低碳醇、同碳数油品具有较高的经济价值。本申请提出采用液相还原法制备高分散负载型Cu-Fe双金属纳米催化剂用于提高费托合成高碳醇选择性。通过改变载体种类、制备还原温度、分散剂、还原剂、络合剂的种类及用量，得到负载型Cu-Fe双金属纳米催化剂的制备方法和制备工艺，并结合催化剂表征技术建立载体、还原温度、分散剂、还原剂、络合剂等与催化剂微观结构、粒度与分散度及反应性能间的构-效关系；采用原位表征、分析技术与DFT计算结合的方式，探讨费托合成联产高碳醇反应过程碳链增长及含氧化合物生成过程，明确费托合成反应过程高碳醇的生成机理，并建立包含高碳醇在内的费托合成集总反应动力学模型。本项目研究成果不仅有助于深入理解费托合成反应过程及高碳醇生成机理，还可用于指导费托合成纳米催化剂的优化设计和开发，为催化剂及反应器放大提供基础理论支持。

本项目采用液相还原法制备了具有高分散度的负载型Cu-Fe双金属纳米催化剂，研究了载体种类、制备温度、分散剂（络合剂）、还原剂的种类及用量、活性金属负载量及Cu/Fe对催化剂反应性能的影响，分析探讨了催化剂制备工艺与微观结构及反应性能间的构-效关系，得到了较优的负载型Cu-Fe双金属纳米催化剂的制备方法和制备工艺；采用原位实验及DFT计算，分析了CO活化路径、CO插入反应中间体的存在形态等，获得了较合理的费托合成CO活化及高碳醇生成反应机理，并基于此建立了包含高碳醇在内的费托合成集总反应动力学模型。研究成果有助于深入理解费托合成反应过程及高碳醇生成机理，可用于指导费托合成纳米催化剂的优化设计和开发，为催化剂及反应器放大提供基础理论支持。