共查询到20条相似文献,搜索用时 125 毫秒
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<正> 高分子催化剂作为功能性高分子的重要组成部分具有许多独特的优点和功能,是目前催化剂研究的发展方向之一,日益受到重视。 Neckers等将AlCl_3与聚苯乙烯反应制成的高分子载体催化剂,对酯化、缩醛等反应有较好的催化作用,我们也曾制备了一系列聚苯乙烯与强Lewis酸的复合物催化剂,如聚苯乙烯-五氯化锑复合物(Ps-SbCl_5)、聚苯乙烯-四氯化钛复合物(Ps-TiCl_4)、聚苯乙烯-四氯化锡复合物(Ps-SnCl_4)、聚苯乙烯-三氯化铁复合物(Ps-FeCl_3)等,它们具有较高的稳定性和良好的催化效能.为了研究弱Lewis酸与高分子载体的复合能力以及它们是否还具有催化活性,为了研究各种Lewis酸用高分子载体固载化的规律 相似文献
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钯系高分子载体催化剂对硝基苯液相加氢催化活性的研究 总被引:2,自引:0,他引:2
制备了以弱碱性(AH-1、AH-2ХH)、中等碱性(AH-31、ЭⅡЭ-10∏)以及强碱性(AB-17-8、AB-16ΓC)等阴离子交换树脂为载体的钯系催化剂,测定了它们硝基苯催化加氢的活性,其中Pd-AH-1、Pd-AB-16ГC和Pd-AB-17-8的活性较好。本文还分析了树脂结构对催化活性的影响。 相似文献
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本文综述了高分子负载型催化剂近年来在以下几方面的进展:(1)催化活性物质在高分子上,特别在功能高分子上的锚定。(2)高分子骨架的“大分子效应”,如高分子链段的疏水效应,高分子网络对活性中心的隔离效应。(3)用ESR、XPS、IR、EXAFS等方面表生催化活性组份。(4)在酸碱催化、氢化及氧化等方面的重要作用。 相似文献
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以硅胶球为基质键合γ-GOPS并各接枝上具有络合功能的三种配体,邻位氨基吡啶、间酰氨基吡啶及对酰氨基吡啶,再和TiCl_4络合成固载化的Lewis酸催化剂,将这些催化剂进行缩醛、缩酮及酯化反应,有很好的催化活性,重复使用多次不失效.本文在合成此类催化剂的过程中利用热失重(TG)法及等离子光谱法(ICP)等检测方法对合成此类催化剂的每一步进行跟踪检测,得到键合反应,开环反应及络合反应过程中的键合量,开环相量和TiCl_4络合量的定量数据.对固载化催化剂表面的接枝量有所了解,从而可进一步检测此类催化剂的催化效应并得到一些启示. 相似文献
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铁系固体酸催化剂的制备及催化合成水杨酸酯 总被引:5,自引:0,他引:5
制备了铁系固体酸催化剂(Ⅰ)并将其用于催化合成水杨酸酯,优化了反应条件:当Ⅰ用量为投料质量的6.1%,mol酸:mol醇=1:4,适当提高反应温度,合成水杨酸戊酯的反应时间可缩短至3h,产率达91.3%。合成其它水杨酸酯时也取得很高的产率。通过对比,Ⅰ的催化酯化能力优于Fe2O3/SO4^2-固体超强酸催化剂,套用6次后催化性能基本保持不变。 相似文献
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固载杂多酸盐催化剂的制备与性能研究 总被引:5,自引:1,他引:4
介绍了固载型杂多酸盐催化剂TiSiW12 O4 0 /TiO2 的两种制备方法 ,并以乙酸正丁酯的合成 ,考察了制备条件对其催化活性的影响 ,结果令人满意 相似文献
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活性炭负载钌基氨合成催化剂的制备和催化活性 总被引:29,自引:1,他引:29
A series of active carbon supported ruthenium based catalysts, promoted by alkali and alkaline earth nitrate, are prepared by impregnation method and with RuCl 3·3H 2O as precursor. Effects of support, promoter and preparation conditions on catalytic activity are discussed. The catalytic activity is evaluated with a fixed bed micro reactor at lower pressure. The results show that the impregnation sequence affects the catalytic activity obviously. Ba Ru K/C is the preferred impregnation sequence. And effects of nature, producing area and pre treatment of the support on catalytic activity are also examined. Catalytic activity increases with the amount of Ru deposited on the support, it attains maximum when Ru loading is 8%. Optimal molar ratio of promoter to Ru is 10. 相似文献
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新型固载化螯合钛酸酯的合成及催化酯化性能的研究 总被引:3,自引:1,他引:3
新型固载化螯合钛酸酯的合成及催化酯化性能的研究1)车丕智刘继红王春凤邢伯军孔祥球(哈尔滨师范大学化学系哈尔滨150080)刘洪贵(哈尔滨市第六中学哈尔滨150036)宋英(哈尔滨工业大学应用化学系哈尔滨150006)关键词固载化螯合钛酸酯催化剂酯化分... 相似文献
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合成条件对磷钨杂多酸季铵盐催化剂性能的影响 总被引:8,自引:0,他引:8
采用廉价的季铵盐[C16H33(CH3)3(70%)+C18H37(CH3)3(30%)]N+Cl-(简记为Q+Cl-)代替[C5H5NC16H33]+Cl-作为相转移剂,制备了一种新型的反应控制相转移催化剂,详细考察了制备过程中各因素对催化剂性能的影响,确定了适宜的催化剂制备条件,同时对催化剂的 31P NMR上的各峰进行了归属. 研究结果表明,在1-辛烯环氧化反应中,催化剂各组分在双氧水作用下能够相互转化形成合适比例的多组分复合催化剂,催化活性较高,但任一组分单独作用时催化活性则较低. 相似文献
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石墨负载Pt催化剂的制备、表征及活性研究 总被引:1,自引:0,他引:1
Pt/graphite catalyst was prepared by incipient wetness impregnation using H2PtCl6·6H2O as precursor. The catalyst was characterized by SEM, XRD, XPS and its degradation ability for oxalic acid was evaluated. The preparation parameters, including the reduction temperature, Pt loading and pyrolysis were studied. The optimal preparation conditions were 350 ℃ with Pt loading of 1.0%. Results show that the loading of Pt can significantly enhance catalytic activity of graphite and that Pt/graphite catalytic ozonation can effectively remove oxalic acid in aqueous solution. The BET surface area of graphite is much smaller than that of activated carbon, however, the catalytic activity of Pt/graphite towards oxalic acid degradation is higher than that of Pt/AC. The XPS results indicate that the active phase at catalyst surface is in the form of Pt0. Compared with that of reduction process in hydrogen, the activity of Pt/graphite catalyst decreases when it is prepared by pyrolysis in air due to the lower Pt dispersion on graphite surface. 相似文献
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A novel carbon based strong solid acid catalyst has been synthesized successfully. The catalytic activity for acetalization and ketalization was investigated. The results showed that the novel catalyst was very efficient with the average yield over 92%. The novel heterogeneous catalyst also has the advantages of high activity, wide applicability even to the preparation of 7 membered ring acetals and ketals, strikingly simple workup procedure, non-pollution and reusability, which will contribute to the green process greatly. 相似文献
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IntroductionThepurposeofthisstudyistosearchforabettercatalystforthesynthesisofolefinsfromCOandH2.SomeresearcheshaveindicatedthatFe-Mnoxideandlron-carbonidecatalystscou1dimproveitsselectivitytoo1efins[I'2].BasedontheFe/Cultrafineparticle(UFP)obtainedbymeansoflaserpyrolysismethod,thispaperreportsthepreparationofaseriesofFe-C-MnUFPcatalysts.ExperimentallCatalystpreparationHighlydispersedamorphousFe/CUFPwaspreparedbymeansoflaserpy-rolysistechnique['1andthenwashedanddried.Certainamountsof… 相似文献
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