【作者】 胡少伟；

【导师】 吕连海；

【作者基本信息】 大连理工大学 ， 应用化学， 2009， 硕士

【摘要】 本文采用骤冷法制备了Ni-Al-Mo合金薄条,经粉碎、碱活化后得到改性的骨架镍,采用XRD对其进行了表征。将改性骨架镍催化剂用于催化2,4-二甲基硝基苯和3,4-二甲基硝基苯加氢制备相应的芳胺。系统地研究了溶剂种类、反应温度、反应压力、底物浓度、催化剂用量等条件对2,4-二甲基硝基苯和3,4-二甲基硝基苯加氢反应的影响。结果表明,改性骨架镍对以上反应具有优异的催化性能,与文献报道相比,反应条件更加温和,产品收率更高,具有潜在的工业化价值。将改性骨架镍用于催化2,4-二甲基硝基苯加氢制备2,4-二甲基苯胺,催化剂显示出极高的活性和选择性。以乙醇为溶剂,原料初始浓度为2.5mol·L^-1,催化剂的用量为原料质量的6%,在40℃,1.0MPa的下反应130min,2,4-二甲基硝基苯的转化率为100%,2,4-二甲基苯胺选择性可达100%。改性骨架镍催化剂具有良好的稳定性,催化剂连续套用16釜后仍具有很高的活性。将改性骨架镍用于3,4-二甲基硝基苯的液相催化加氢,结合GC跟踪反应过程,探讨了可能的反应历程。得到了优化的反应条件:以甲醇为溶剂,原料初始浓度1.0mol·L^-1,催化剂质量为原料质量的7%,在60℃、0.5MPa下反应40min,3,4-二甲基硝基苯的转化率和3,4-二甲基苯胺的选择性均达到100%。对催化剂进行寿命实验考察,结果表明该催化剂具有很高的稳定性。反应得到的产品纯度高,色相好,市场竞争力强。更多还原

【Abstract】 In this thesis, the rapid quenching technique was introduced into the production of Ni-Al-Mo alloy ribbon. After crushing, ball milling and extracting Al by alkali, modified skeletal Ni was obtained. The catalyst was characterized by XRD and employed for the hydrogenation of 2,4-dimethylnitrobenzene and 3,4-dimethylnitrobenzene. The effects of reaction parameters including solvent type, temperature, pressure, initial concentration of the substrate and amount of the catalyst were investigated in the above two substrates’ reaction system. Modified skeletal Ni catalyst showed excellent catalytic properties. Compared with that in literatures, the yield of the products was higher while the conditions were milder. So the crafts have great potential value in industry.The modified skeletal Ni was proved to be very active and selective for the hydrogenation of 2,4-dimethylnitrobenzene to 2,4-dimethylaniline. Under the optimized conditions of m（catalyst）/m（substrate） = 6% in ethanol, initial concentration of the substrate = 2.5mol·L^-1, 1.0MPa and 40℃, the conversion of 2,4-dimethylnitrobenzene in 130min was up to 100%, and the selectivity of 2,4-dimethylaniline was as high as 100%. The modified skeletal Ni exhibited good stability, and it maintained high activity even after 16 times batch-running.The modified skeletal Ni was also used for liquid phase hydrogenation of 3,4-dimethylnitrobenzene. The reaction process was monitored by gas chromatography, and the hydrogenation pathway was discussed. Under the optimized conditions〔m（catalyst）/ m（substrate） = 7% in methanol, initial concentration of the substrate = 1.0mol·L^-1, 60℃and 0.5MPa〕, both the conversion of 3,4-dimethylnitrobenzene and the selectivity of 3,4-dimethylaniline were up to 100% in 40 minutes. The life of catalyst was investigated and the catalyst showed good stability. Meanwhile, the product exhibited excellent hue with high purity, which enhances its market competitiveness.更多还原