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An efficient and environmentally friendly procedure was described for easy product isolation for the oxidation of cyclohexane with tert-butyl-hydroperoxide catalyzed by titanium silicalite 1 (TS-1) in ambient-temperature ionic liquid [emim] BF4. Good yield and higher selectivity of products were found in the ionic liquid compared with in molecular solvent. The research results showed 13.2% conversion of cyclohexane, 97.6% cyclohexanol and cyclohexanone selectivity were obtained in ionic liquid under mild conditions of 90℃. 相似文献
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碱式碳酸镁微观结构对视比容影响 总被引:1,自引:0,他引:1
树脂基摩擦材料普遍存在热衰退问题,探索解决摩擦材料的热衰退问题一直是摩擦材料研究的热点。无机黏结剂具有承受高温的特点,有望替代树脂黏结剂成为摩擦材料用黏结剂的材料。采用硅酸盐作为黏结剂,丁腈橡胶为韧性改良组分,采用热压成型工艺制备了摩擦材料。研究了硅酸盐种以氢氧化镁和二氧化碳为原料,采用加压碳化法制备碱式碳酸镁。考察了二氧化碳分压、反应温度、搅拌转速和反应时间对碱式碳酸镁颗粒形貌影响,同时探究了碱式碳酸镁微观结构对其视比容的影响。采用扫描电子显微镜、X射线衍射仪、热分析仪对产物的形貌、物相和热分解做了表征。结果表明:二氧化碳分压为0.6 MPa、反应温度为90 ℃、搅拌转速为200 r/min、反应时间为2 h得到的碱式碳酸镁为大小均匀、片层交叉堆积的规则球体,其视比容最高为10.54 mL/g。类及用量、橡胶含量对摩擦材料冲击韧性和摩擦磨损性能的影响,借助扫描电子显微镜(SEM)观察摩擦材料磨损表面的形貌并分析磨损机理。结果表明:钠钾比(物质的量比)为2∶1的混合硅酸盐制备的摩擦材料基体间的结合力较强,综合性能最优;适当含量的硅酸盐可以为摩擦材料提供较好的强度和韧性,并且可以实现摩擦材料的摩擦系数在全部测试温度范围内的平缓稳定,有效地改善了摩擦材料的抗热衰退性能;适量橡胶的加入可以提高摩擦材料的冲击韧性。 相似文献
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负载金属改性活性炭纤维的脱硫性能 总被引:6,自引:0,他引:6
Metal-loaded activated carbon fibers (ACFs) were prepared by impregnation and characterized by N2 adsorption at 77K, XRD, XPS and SEM. Their properties on SO2 removal were examined in a tubular fixed bed reactor with a model flue gas. Cobalt-loaded ACF showed the best activity among the prepared metal-loaded ACFs and a constant removal ratio of SO2 above 87% during continuous exposure to the flow of SO2/O2/H2O/N2 at 45℃ for more than 216h. The characteristic of the prepared loaded-ACFs showed that the exceptional activity of Co-ACF was attributed to the high amount of active sites due to modification by loading cobalt. 相似文献
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在不同工艺条件下对脱除柠檬酸酸化液中SO4^2-进行了研究,确定了适宜反应温度、时间及脱除剂加入量。使柠檬酸酸化液中SO4^2-含量达到0.007g/L,满足了工业生产要求。并且降低了成本,减小了碱液对环境的污染。 相似文献
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羰基硫在氢氧化钠水溶液中的水解动力学 总被引:1,自引:0,他引:1
常压下、温度20~50℃,测定了鼓泡反应器中羰基硫(COS)在1.3130~4.4038mol/LNaOH水溶液中的水解速率,获得一级快速不可逆反应的水解速率表达式,其表观活化能为59.63kJ/mol. 相似文献
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使用硫酸钠、氯化钡和纳米硫酸钡晶种为原料,制备得到了亚微米级硫酸钡产品。通过使用扫描电子显微镜、激光粒度仪等分析手段,系统研究了工艺条件对于产品硫酸钡颗粒的形貌、粒径及粒度分布的影响。实验结果表明:随着反应物浓度的增大,产物硫酸钡粒子的粒径逐渐减小,且粒度分布逐渐变窄;两种反应物同时加入的加料方式所得产品粒径较大且粒度分布较宽;反应温度的升高也会导致产物颗粒粒径增大、粒度分布变宽。将0.5 mol/L氯化钡溶液滴加入含有纳米硫酸钡晶种的0.5 mol/L硫酸钠溶液中,保持反应温度为40℃,可以得到粒径为260 nm左右的硫酸钡颗粒。 相似文献
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Heterogeneous oxidation of cyclohexane by tert-butyl hydroperoxide (TBHP) was carried out over ZSM-5 catalysts with different Si/Al ratios in ionic liquids and organic molecular solvents. Higher yield and selectivity of the desired products were found in ionic liquids than in molecular solvents. The conversion of cyclohexane exhibits a decrease from 15.8% to 10.8% with the increase of Si/Al ratio of the HZSM-5 catalyst, and all the catalysts exhibit good selectivity of monofunctional oxidation products at around 97%. The activity of catalyst is found strongly de-pendent on the alkyl chain length of ionic liquid. 相似文献