【作者】 高丽雅；

【导师】 王延吉；

【作者基本信息】 河北工业大学 ， 化学工艺， 2012， 博士

【摘要】 在化工生产中，从初始原料到获得终端产物，通常要经过多步反应工艺过程才能实现。这势必导致反应和分离装置多、工艺流程长、生产效率低、能耗高和废物排放增加。另外，在此过程中往往存在易燃、易爆及有毒、有害等非安全过程产物。去除非安全化学品生产和使用的直接反应过程是解决上述问题的有效途径之一；芳香胺类和芳香酚类化合物均为重要的基本有机化工原料。传统的生产方法存在合成路线长、工艺复杂、原子利用率低，副产物多、过程不安全及环境污染等问题。本文基于高效—清洁—安全的化工过程理念，较系统地研究了芳烃与羟胺直接催化合成芳香酚（胺）类化合物的反应过程。包括催化剂设计与制备、新合成反应路线、反应产物调控及环境友好离子液体的应用等。甲苯与羟胺直接催化合成甲基苯胺的新负载型催化剂设计与制备：相对于传统合成方法，该工艺去除了甲苯硝化及硝基甲苯氢化等不安全工艺过程。考察了钒酸盐（NaVO₃、NH₃VO₃）和钼酸盐(Na₂MoO₄、（NH₄）₆Mo₇O₂₄)等均相催化剂的甲苯氨基化反应性能。发现以钒酸盐和钼酸盐为催化剂时，对应的适宜溶剂分别为乙酸-水溶液和乙酸-硫酸溶液，其最佳体积比分别为乙酸/水=2/1和硫酸/乙酸=4:11。钼酸盐为催化剂时，甲基苯胺收率最高可达到80%；在均相催化剂研究基础上制备了负载型催化剂，考察了载体对合成甲基苯胺反应性能的影响。弱酸性载体催化剂V₂O₅/Al₂O₃、MoO₃/Al₂O₃上甲基苯胺的收率与均相催化剂相当，且显著减少了活性组分用量；针对钒酸盐均相催化剂，考察了助剂对反应性能的影响。加入硫酸铜助剂（V/Cu=16/1）使甲基苯胺收率明显提高；成功地制备出了一种新的负载型催化剂CuO-V₂O₅/Al₂O₃，在乙酸-水溶剂中，反应温度85C，常压，反应时间4h的优化条件下，甲基苯胺的收率高达60.3%；采用XRD、XPS、XRF等方法对负载型催化剂进行了表征，V₂O₅以无定型状态高度分散于催化剂中，Cu以+2价态形式存在于催化剂表面，Cu的引入，改变了V的表面物理化学环境，使更多的V5+物种在催化剂表面形成，进而提高了合成甲基苯胺的反应活性。芳烃与羟胺直接催化合成芳香酚的新合成路线研究：相对于以N₂O、O₂、H₂O₂等为氧化剂的直接合成方法，该工艺路线更为安全。明确提出了芳烃与羟胺直接催化合成芳香酚的新合成路线；以（NH₄）₆Mo₇O₂₄·4H₂O为催化剂，研究了不同反应溶剂对甲苯与羟胺合成甲基苯酚反应性能的影响。发现在乙酸-硫酸溶剂中加入水可明显提高甲基苯酚的选择性。在此基础上，考察了不同水含量的水-乙酸-硫酸溶剂中合成甲基苯酚的反应性能，确定出其适宜的体积比为水/乙酸/硫酸=4/10/1。优化了操作条件，在甲苯与羟胺摩尔比为1:1，反应温度80C，常压，反应时间4h条件下，甲苯转化率及甲基苯酚的选择性分别为36.3%和61.3%；将上述合成方法推广到其它芳香酚的合成，发现以（NH₄）₆Mo₇O₂₄·4H₂O为催化剂时，苯、乙基苯、二甲苯（邻、对、间）等芳香烃，均可以与羟胺反应一步合成相应的酚类化合物。其转化率分别为51%，13%和17%，生成对应的酚类化合物选择性分别为45%，74%和70%以上。离子液体-乙酸-水环境友好的新反应溶剂研究：采用环境友好的酸性离子液体替代合成芳香酚类反应溶剂中的硫酸，并将其与钼系催化剂结合建立一种离子液-钼（ILs-Mo）催化体系；合成了一系列的SO₃H-型离子液体，并将其用于苯酚、甲基苯酚和对二甲基苯酚的直接合成反应。结果表明，在1-磺丁基-3-甲基咪唑三氟甲磺酸盐离子液体-乙酸-水（其重量比为6:8:8）所组成的的反应溶剂中，（NH₄）₆Mo₇O₂₄·4H₂O为催化剂，苯、乙苯及对二甲苯均可以与羟胺直接反应合成相应的芳香酚类化合物。其中，对二甲基苯酚的选择性接近100%。考察了该催化剂体系的重复使用性能。反应后只需用乙醚萃取产物，催化体系即可循环使用，并且催化体系保持良好的稳定性。更多还原

【Abstract】 Generally, a multi-stage reaction system is needed to produce a product from startingmaterial in chemical manufacturing process. However, these processes have severaldisadvantages such as multi-step procedures, more devices needed for reaction and separation,low production efficiency, high energy consumption and waste discharge. Evenmore, there alsoexist unsafe intermediate products such as inflammable or explosive compounds, toxic andharmful substances. To aovid producing and using the unsafe intermediate products, directsynthesis process is a better way to solve these problems. Aromatic amines and phenols arevaluable intermediate for organic synthesis. Traditional ways for producing these compoundsinvolve multi-step processes, suffering from the drawbacks like low atomic utilization,producing more side products, unsafe process and environmental pollution, etc. Based on theidea of high efficiency, clean and safety chemical process, a direct process for the production ofphenols （aromatic amines） was investigated in this study, including catalyst design andpreparation, new catalytic reaction, regulation of product distribution and the application of ionicliquid.New supported catalyst design and preparation for direct catalytic synthesis oftoluidines from toluene and hydroxylamine: Comparson with traditional synthetic routes,unsafe process including nitration of toluene and hydrogenation of nitro-toluene, were removedfrom this process. Then a series of vanadium （NaVO₃、NH₃VO₃） and molybdenum salts(Na₂MoO₄、（NH₄）₆Mo₇O₂₄) were used as catalysts and tried for amination of toluene. The resultsshowed that different catalysts need different reaction media to show higher activity. A suitablesolvent is HOAc-H₂O acid media （v/v=2:1） for vanadium catalysts, and that, for molybdenumcatalysts, is H₂SO₄-HOAc solution （v/v=4:11）. Moreover, the highest yield of toluidines above80%was obtained on the molybdenum catalysts. Based on the research on the activity ofhomogeneous vanadium-based catalyst, supported vanadium catalysts were prepared, and the effect of carrier and promoter on the catalyst activity was investigated in the reaction of tolueneamination. It was found that carriers with weak acidity have a beneficial effect on the catalystactivity. Furthermore, adding Cu species to vanadium catalysts shows a peculiar behavior,maintaining a high activity toward toluene amination. An optimum Cu/V ratio appears at lowdopant loading （V/Cu=16/1）. Subsequently, new supported vanadium catalysts CuO-V₂O₅/Al₂O₃were prepared prepared, and characterized by various techniques such as XRF, BET, XPS andXRD. The optimized reaction conditions investigated were HOAc:H₂O （v/v）2:1, conducted at85°C for4h. More than60%total yield of toluidines was obtained under the optimizedconditions. Catalyst characterizations revealed that V₂O₅phase was in a highly dispersed state onthe catalyst. Copper was present mainly in the+2valence, and the addition of copper improvedthe formation of V5+species, thus enhancing the activity of the catalyst. This may be due tophysical or chemical change in the environment of the vanadium species by the introduction ofCu species.A new approach for direct catalytic synthesis of phenols: Currently there are severalapproaches, involving direct oxidation of aromatics employing N₂O, O₂, and H₂O₂as oxidant.However, the present route was more safe for direct synthesis of phenols. In this work, a newapproach was proposed for direct catalytic synthesis of phenols from aromatics andhydroxylamine. Initially, the reaction between toluene and hydroxylamine catalyzed by（NH₄）₆Mo₇O₂₄·4H₂O was selected as a model reaction for optimizing the reaction conditions.The results showed that the incorporation of water into HOAc-H₂SO₄acidic media wouldimporved the selectivity for cresol. Thus the reaction was conducted in variousH₂O–HOAc–H₂SO₄solvents containing different amount of water. The best result is obtained fora H₂O/HOAc/H₂SO₄volumeratio of4:10:1. The optimized reaction conditions investigated wereNH₂OH/toluene （molar ratio）1:1, conducted at80°C for4h. And high toluene conversion andcresol selectivity were obtained, corresponding to36.3%and61.3%respectively. Moreover, avariety of aromatics including benzene, ethylbenzene and xylene, were examined. And thesearomatics could be hydroxylated with hydroxylamine to give the corresponding phenols. Theconversion of benzene, ethylbenzene and xylene were51%,13%and17%respectively, and theselectivity for the corresponding phenols were all above45%,74%and70%.A new environmental friendly reaction medium of ILs-HOAc-H₂O media: The aim ofthis study was to explore the possiblity of using ILs as a media to replace sulfuric acid in thereaction of direct synthesi of phenol, cresol and2,5-xylenol. And Several SO₃H-functionalizedILs was prepared. Then an eco-friendly and reusable catalytic system, i.e., combination of thenew reaction media with Mo catalyst （called ILs-Mo catalytic system）, was designed for aromatics hydroxylation. It was found that [HSO₃-bmim][CF3SO₃]-HOAc-H₂O solution with aweight ratio of6:8:8was a better reaction media for the hydroxylation using（NH₄）₆Mo₇O₂₄·4H₂O as catalyst. And all the aromatics including benzene, ethylbenzene andxylene could be hydroxylated with hydroxylamine to give the corresponding phenols.Furthermore, high selectivity （nearly100%） of2,5-xylenol was achieved in this catalytic system.All the organic compounds could be entirely extracted by ether, and the residue including ILsand Mo catalyst can be used again. Recycling experiments suggested that the catalytic systemwas stable enough to be recycled for the hydroxylation.更多还原