植物油一步定向合成航空燃料催化剂合成及反应机理研究

The development tendency and research highlights of aviation fuel is to produce the green biojet fuel from the renewable resource. Moreover,it is a great challenge to develop a technology to synthesize green jet fuel by one-step route from lipids. The vital process of this technology is to design and develop a multifunctional hierarchical catalyst. However, there is no corresponding theory to direct the R&D of this multifunctional catalyst. In this work, a dual-porogen structure-direting agent based on controlled-grafting multiwalled carbon nanotube will be constructed and used to synthesize hierarchical ZSM-5 zeolite. The controllable method will be developed to tailor the structure and acidity distribution of hierarchical ZSM-5 zeolite. The shape-controlled synthesis of Pt-Ni nanocrsytal and controlled distribution of active metal in hierarchical ZSM-5 zeolite will be developed.The stability mechanism of active metal and the influence of metal-support interaction by hierarchical structure will be achieved. The hydroconversion of model compounds and the real plant oils such as oleic acid, glycerol trioleate,Jatropha oil, wasted cooking oil and algae oil will be investigated. The influence, action mechanism and oriented regulation of hierarchical structure and acidity distributioin as well as actvie metals and synergy of metals on the reactions of deoxygenation, hydrogenation,selective cracking, aromatization and isomerization will be obtained. Combined with the in-situ FTIR analysis,the reaction mechanism and kinetics of the hydrodeoxygenation of vegetable oils will be developed.The reaction-oriented regulating method will be constructed.The aim of this work is to disclose the nature and the mechanism of the conversion of vegetable oils to hydrocarbons in sigle-step on the hierarchical catalyst and the relative fundamental theories, so as to provide some valuable theoretical guidance on designing and developing novel high performance multifunctional catalysts materials as well as on their applications.

开发绿色生物质燃料是航空燃料的发展趋势和研究热点，植物油一步转化合成是其中最具挑战性的方法，该过程的关键是设计合成多功能级孔催化剂，然而目前尚缺乏相应的理论基础。本研究拟通过可控接枝碳纳米管构建双孔模板剂合成级孔ZSM-5催化剂，建立其结构和酸分布的调控方法；通过建立Pt-Ni晶形可控合成及活性金属在级孔ZSM-5载体上定向分布调控方法，获得级孔结构对金属活性位的稳定作用机理及金属-载体相互作用的影响；通过研究模型化合物及真实植物油的催化过程，获得催化剂级孔结构与酸分布、活性金属及金属协同作用对脱氧、加氢、选择性裂化、芳构化和异构等反应的影响规律、作用机理及定向调控；结合原位红外等在线分析，获得其反应机理及动力学，进而构建级孔催化剂定向合成及反应调控技术。本研究旨在揭示级孔催化剂在催化植物油一步加氢转化过程中的作用机理及相关基础理论，以期为新型高效级孔催化剂的设计、开发和应用提供理论指导。

本文以催化剂的活性金属和载体为研究对象，深入探讨了活性金属和载体在植物油氢化脱氧中的作用，完成了碳纳米管可控接枝改性研究；在探索微孔模板剂TPABr研究基础上，进一步探究了大分子结构的微孔模板剂甲基三辛基氯化铵（A336）和更大分子结构的模板剂十六烷基三甲基溴化氨（CTAB）在纳米碳管表面的接枝过程影响规律，详细探索了碳纳米管模板剂合成ZSM-5过程。研究了碳纳米管与TPABr混合模板剂和TPABr接枝到碳纳米管上作为模板剂合成级孔ZSM-5两种过程，建立了可控有序级孔结构分子筛催化剂的合成技术。通过探索Pt源、胺浓度对Pt纳米晶的影响，完成了纳米Pt的可控合成；通过活性组分表面调控策略和Pt-Ni的协同效应，构建了高效PtNi催化剂；建立了级孔载体上活性金属分布调控技术。研究了级孔结构对金属活性位的稳定性的影响及作用机理。分别以Ni和Ni掺杂Pt，Mo或W为活性金属，研究了活性金属分布对加氢脱氧路径选择性的影响，结果表明NiPt双金属催化剂的氢化脱氧路径主要为脱羧和加氢脱羰，脱羧选择性最高到62%；NiMo双金属催化剂的氢化脱氧路径主要为脱羧和加氢脱氧，脱羧选择性最高到41%。获得了级孔结构及酸分布对脱氧、裂解、芳构化和异构反应的调协机制；研究了模型化合物油酸在Ni表面位的脱氧机理，和金属掺杂对模型化合物油酸加氢脱氧机理的影响，并对Ni掺杂W的催化剂进行了动力学研究，Ni金属和WO3的紧密联系促进了羧基的脱氧，提高了植物油脱氧反应速率常数；获得了麻风树油一步转化制备芳烃的反应机理；建立了油酸一步转化定向合成航空煤油烷烃组分，制得了以链烷烃为主的航空煤油燃料，并探究了层厚度，酸分布对脱氧、选择性裂化反应和异构反应的影响，提高有机液相的收率和C9-C15烃类的选择性（46 %）。因此，调整载体的孔道结构和酸性分布是定向植物油氢化脱氧合成高性能燃料的有效手段。这些研究成果为调控植物油氢化脱氧合成高性能生物质燃料提供一定的理论指导。