共查询到18条相似文献,搜索用时 656 毫秒
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开链冠醚基二芳醛在酸性条件下与氨基硫脲反应,合成了链状冠醚二芳醛缩氨硫脲类化合物,产率80%以上,产物经由IR,MS和元素分析鉴定了其结构。 相似文献
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含间苯二酚类杯[4]芳烃的合成方法研究 总被引:1,自引:0,他引:1
以异戊醛和对羟基苯甲醛及间苯二酚为原料,在浓盐酸的作用下合成了脂肪醛和芳香醛类Resorcarenes化合物。探讨了加样温度、反应温度、反应时间及催化剂含量对反应产率的影响,得到脂肪醛和芳香醛类Resorcarenes化合物的理想合成方法。 相似文献
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氯化钙催化酯化反应机理研究 总被引:1,自引:0,他引:1
以无水氯化钙为催化剂,研究了冰乙酸、异戊醇酯化反应,考察了CaC l2用量对酯化反应的催化效果,同时与浓硫酸催化效果作比较,设计实验对无水氯化钙催化酯化反应的机理进行了探讨,分别得到了24 mL乙酸-18 mL异戊醇-3 g氯化钙、24 mL乙酸-3 g氯化钙和18 mL异戊醇-3 g氯化钙3种反应体系的紫外吸收光谱图,并以强酸消除实验验证催化酯化反应的机理。结果表明,3 g氯化钙与4 mL浓硫酸催化酯化反应得到的产率分别为71.5%和73.6%,催化效果相当,催化机理相同,确认在反应液中形成了强酸性配合物H[CaC l2(CH3COO)],该配合物提供的强酸性是催化酯化反应进行的主要原因。 相似文献
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聚醚酮酮的合成与性能研究 总被引:1,自引:0,他引:1
在温和条件下,以1,2-二氯乙烷为溶剂、无水三氯化铝为催化剂、二苯醚和对苯二甲酰氯为原料合成了高分子量的聚醚酮酮(PEKK),并找到了用浓盐酸脱除催化剂、乙醇提纯聚合物的有效途径。测试了PEKK的主要物理和化学性能,其中PEKK的特性粘度可达0.8~1.0,达到了工程材料的要求。 相似文献
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以电石法乙炔氢氯化失活低固汞催化剂为基础,在等温固定床反应器中模拟实际生产转换器单管装置,对失活催化剂通入高纯无水氯化氢气体,研究在氯化氢气体作用下,失活低固汞催化剂的再生效果,并考察再生温度、再生压力、空速以及再生时间对低固汞催化剂再生后汞含量、碘吸附值、四氯化碳吸附值、载体BET比表面积以及催化性能的影响。结果表明,在再生温度220℃、再生压力100 k Pa、空速500 h~(-1)和再生时间60 h条件下,失活低固汞催化剂再生性能最好,再生后乙炔转化率达到99.8%。 相似文献
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Claudia Menini Colin Park Eun-Jae Shin George Tavoularis Mark A. Keane 《Catalysis Today》2000,62(4):355-366
Catalytic hydrodehalogenation is presented as a viable approach in the non-destructive treatment of concentrated halogenated aromatic gas streams to generate reusable raw material. Nickel loaded (from 1.5 to 20.3% w/w) silica catalysts have been used to hydrotreat a range of halogenated feedstock, where 473 K≤T≤573 K: chlorobenzene, chlorotoluene, chlorophenol, bromobenzene, dichlorobenzene, dichlorophenol, trichlorophenol, pentachlorophenol. The long term (up to 800 h-on-stream) stability of these catalysts has been assessed where the changes in nickel particle size and morphology as a result of the prolonged catalytic step was probed by TEM; each catalyst irrespective of any loss of initial activity was fully selective in solely promoting dehalogenation. In the case of a polychlorinated feedstock, dechlorination can proceed in a stepwise manner to generate a partially dechlorinated product. Hydrodehalogenation appears to occur via an electrophilic mechanism where the presence of electron-donating substituents on the benzene ring enhances the rate of reaction. The reaction is shown to be structure sensitive over Ni/SiO2 where the hydrodechlorination rates and ultimate yield of the parent aromatic from a polychlorinated reactant is favored by larger nickel particle sizes. A direct contact of the freshly activated catalyst with HCl or HBr gas induced an appreciable growth of the supported metal crystallites. Chlorobenzene hydrodechlorination was suppressed on a HCl or HBr treated Ni/SiO2 which promoted instead the unexpected growth of highly ordered carbon filaments; this carbon growth is characterized by TEM and SEM. The dependence of the experimental hydrodechlorination and hydrodebromination rates on the gas phase aromatic partial pressure (in the range 0.02–0.1 atm) is adequately represented by a kinetic model involving a non-competitive adsorption of hydrogen and halogenated aromatic where the incoming aromatic reactant must displace the hydrogen halide from the catalyst surface. 相似文献