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磷钨酸催化过氧化氢氧化环己酮/环己醇合成己二酸 总被引:3,自引:0,他引:3
在无溶剂、无相转移催化剂条件下,用钨酸钠或磷钨酸为催化剂,30%过氧化氢作氧源,在一定温度下可以将环己酮或环己醇,环己酮混合物高产率地氧化成己二酸。讨论了30%过氧化氢的量、反应时间、反应温度、催化剂用量、醇酮比和草酸对己二酸产量的影响。结果表明:反应温度为90℃,30%H2O2为0.4mol,草酸作酸性配体,钨酸钠催化氧化环己酮反应12h,制得的己二酸的最大产率仅为71.8%。而磷钨酸作催化剂反应8h,己二酸的最大产率高达95.1%。同时,不用酸性配体,磷钨酸对环己酮或环己酮,环己醇混合液也表现出很高的催化活性,在优化条件下己二酸产率可达87.5%或82%。 相似文献
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钨酸催化氧化环己醇合成己二酸 总被引:4,自引:1,他引:3
以钨酸-酸性添加剂为催化体系,在无有机溶剂和相转移剂的情况下,催化30%过氧化氢氧化环己醇合成己二酸。结果表明,当钨酸用量为2.5mmol,钨酸:酸性添加剂:环己醇:过氧化氢为1:1:40:176(摩尔比)时,酸性添加剂中,以磺酸水杨酸氧化环己醇效果最佳,反应8h己二酸分离产率达87.8%、纯度为99.9%;而单独以钨酸为催化剂时,己二酸分离产率达65.6%、纯度为97.3%;以酚类-弱酸性化合物为添加剂时,己二酸分离产率均在80%以上。钨酸-磺酸水杨酸催化体系重复使用至第5次,己二酸分离产率仍可达81.5%。 相似文献
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活性炭负载杂多酸催化氧化环己醇合成己二酸 总被引:1,自引:0,他引:1
以活性炭负载杂多酸(H3PW12O40/C)为多相催化剂,用30%(质量分数,以下同)过氧化氢催化氧化环己醇合成己二酸。较系统地研究了催化剂用量、过氧化氢用量及反应时间对产品收率的影响。实验结果表明:催化剂用量为反应物质量的0.3%,30%过氧化氢用量与反应物质量比为6∶1,在回流温度下进行催化氧化反应8 h,己二酸的产率可达88.1%。 相似文献
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杂多酸催化环己醇氧化制备己二酸 总被引:6,自引:0,他引:6
以磷钨酸为催化剂,用过氧化氢氧化环己醇的方法合成了己二酸。探讨了物料配比、催化剂用量、反应温度、反应时间对己二酸产率的影响。在环己醇用量10.5mL,30%过氧化氢溶液用量60mL,催化剂用量0.5mmol,反应温度80℃,反应时间8h的条件下,己二酸产率达70.6%。实验结果表明,这是一种合成己二酸的切实可行的绿色化学工艺。 相似文献
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在无溶剂、无相转移催化剂条件下,用钨酸钠或磷钨酸为催化剂,30%过氧化氢作氧源,在一定温度下可以将环己酮或环已醇/环己酮混合物高产率地氧化成己二酸.讨论了30%过氧化氢的量、反应时间、反应温度、催化剂用量、醇酮比和草酸对己二酸产量的影响.结果表明反应温度为90℃,30%H2O2为0.4 mol,草酸作酸性配体,钨酸钠催化氧化环己酮反应12 h,制得的己二酸的最大产率仅为71.8%.而磷钨酸作催化剂反应8 h,己二酸的最大产率高达95.1%.同时,不用酸性配体,磷钨酸对环己酮或环己酮/环己醇混合液也表现出很高的催化活性,在优化条件下己二酸产率可达87.5%或82%. 相似文献
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采用合成的复合季铵磷钨酸盐为催化剂,以50%双氧水为氧源催化环己烯合成了己二酸,反应结束催化剂能够与反应体系分离和回收套用。考察了反应时间、反应温度、催化剂用量、双氧水与环己烯物质的量比等因素对反应的影响。实验结果表明,在反应温度90~95℃、反应时间8h、n(H2O2)∶n(环己烯)=4.4、n(催化剂)∶n(环己烯)=7∶1000的条件下,己二酸的平均收率达85%,该催化剂重复使用5次后,己二酸产率仍可达到83%。 相似文献
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以N-甲基吡咯烷酮和磷钨酸为原料一步法合成了吡咯烷酮型杂多酸盐[HNMP]PTA催化剂,通过红外光谱、元素分析、质量分析等对其进行了表征,将制得的催化剂用于催化氧化环己烯清洁合成己二酸。探讨了吡咯烷酮型杂多酸盐的催化活性,考察了其用量、反应时间对己二酸合成的影响,并将其催化作用与单纯磷钨酸进行了对比。另外,考察了催化剂的多次催化效果。实验结果表明:吡咯烷酮型杂多酸盐催化剂对于环己烯氧化合成己二酸具有很好的催化效果,在不加其他任何助催化剂,如表面活性剂、各种酸性配体或相转移催化剂前提下,环己烯100 mmol、质量分数30%双氧水44.5 mL、[HNMP]PTA 0.75 mmol、保持回流温度、反应时间8 h条件下,己二酸的分离产率可达90.1%,其催化效果优于单纯的磷钨酸,且催化剂表现出良好的重复使用性能。 相似文献
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钨酸/无机酸性配体催化氧化环己烯合成己二酸 总被引:9,自引:0,他引:9
以钨酸/无机酸性配体为催化体系,在无有机溶剂和相转移剂的情况下,催化过氧化氢(质量分数30%)氧化环己烯合成己二酸。结果表明,以钨酸/磷酸催化氧化环己烯的催化效果最优。当钨酸:无机酸性配体:环己烯:过氧化氢的摩尔比为1:1:40:176,反应8 h时,己二酸产率达88.2%且纯度高;而不使用无机酸性配体时,己二酸产率只有72.1%,产品纯度也较低。当使用磷酸、硼酸为无机酸性配体时,随反应时间的增加,己二酸产率均升高。当磷酸用量为2.5 mmol时,己二酸产率和纯度均较高。 相似文献
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在无有机溶剂、无相转移剂的条件下,以E(H2O2)=30%为氧源,采用原位合成的Na2WO4/1,2,3,4-丁烷四羧酸/H2O2过氧钨酸络合物为催化剂,催化氧化环己烯合成己二酸。考察了酸性配体1,2,3,4-丁烷四羧酸的用量、反应温度和反应时间对反应的影响。当n(1,2,3,4-丁烷四羧酸):n(Na2WO4)=4:1、n(Na2WO4):n(环己烯):n(H2O2)=1:40:176、水浴控制温度(70~90℃)时,反应8h,己二酸分离产率高达85.1%。催化剂重复使用至第5次,己二酸产率仍分别可达80.4%(回流控温)和80.2%(水浴控温70~90℃)。 相似文献
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仿生催化氧气氧化环己烷合成已二酸反应条件的研究 总被引:3,自引:0,他引:3
以环己烷为原料,氧气为氧化剂,仿生催化剂邻氯铁卟啉为催化剂,一步合成己二酸.考察了反应温度、反应时间、氧气压力、催化剂用量等因素对反应的影响,发现上述因素均对己二酸收率有显著影响,且都有一个最佳的值.催化剂邻氯铁卟啉在该反应中有良好的催化活性,且活性转化数很高.优选的反应条件是反应温度为140℃,氧气压力为2 5 MPa,反应时间为8 h,催化剂用量为1.5 mg.在此条件下,己二酸的质量收率可达21.4%,活性转化数可达24 582. 相似文献
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Wenjuan Yan Wenxiang Zhang Qi Xia Shuaishuai Wang Shuxia Zhang Jian Shen Xin Jin 《中国化学工程学报》2020,28(10):2542-2548
Adipic acid is a dicarboxylic acid of great industrial importance, mainly used in the production of nylon-6,6 and polyurethane. The use of nitric acid as an oxidant in the industrial production of adipic acid poses significant carbon footprint to the environment. Clean adipic acid synthesis methods using a heterogeneous catalyst with H2O2 as oxidant and water as solvent have potential advantages of low catalyst cost, easy synthesis and recovery, cleanness and environmental protection. In this work, hexagonal mesoporous silicate materials were synthesized by a sol–gel method and evaluated for cyclohexanol/cyclohexanone oxidation to adipic acid. The physical and chemical properties of Fe-HMS were characterized by XRD, HR-TEM, BET and UV–Vis. The experimental results showed that Fe-HMS materials show pore sizes ranging from 2–3 nm. W- and Mo-based polyoxometalates were also evaluated and compared to the Fe-based HMS catalysts. To improve the adipic acid yield, the influence of the transition metal as well as the effect of metal loading, reaction temperature and catalyst amount on the catalytic performances of Fe-HMS have been investigated in details. When Si/Fe atomic ratio = 100, Fe-HMS catalyst shows the highest activity, with a cyclohexanone conversion of 92.3% and adipic acid selectivity of 29.4%. The reaction pathway of cyclohexanone oxidation was further proposed based on experimental data. 相似文献
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Wenjuan Yan Wenxiang Zhang Qi Xia Shuaishuai Wang Shuxia Zhang Jian Shen Xin Jin 《中国化学工程学报》1982,28(10):2542-2548
Adipic acid is a dicarboxylic acid of great industrial importance, mainly used in the production of nylon-6,6 and polyurethane. The use of nitric acid as an oxidant in the industrial production of adipic acid poses significant carbon footprint to the environment. Clean adipic acid synthesis methods using a heterogeneous catalyst with H2O2 as oxidant and water as solvent have potential advantages of low catalyst cost, easy synthesis and recovery, cleanness and environmental protection. In this work, hexagonal mesoporous silicate materials were synthesized by a sol-gel method and evaluated for cyclohexanol/cyclohexanone oxidation to adipic acid. The physical and chemical properties of Fe-HMS were characterized by XRD, HR-TEM, BET and UV-Vis. The experimental results showed that Fe-HMS materials show pore sizes ranging from 2-3 nm. W- and Mo-based polyoxometalates were also evaluated and compared to the Fe-based HMS catalysts. To improve the adipic acid yield, the influence of the transition metal as well as the effect of metal loading, reaction temperature and catalyst amount on the catalytic performances of Fe-HMS have been investigated in details. When Si/Fe atomic ratio = 100, Fe-HMS catalyst shows the highest activity, with a cyclohexanone conversion of 92.3% and adipic acid selectivity of 29.4%. The reaction pathway of cyclohexanone oxidation was further proposed based on experimental data. 相似文献
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Girendra N. Kulsrestha Uma Shankar Jaipal S. Sharma Jasvinder Singh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1991,50(1):57-65
Liquid-phase oxidation of cyclohexane with Co(III) catalyst and gaseous oxygen was found to be influenced by reaction temperature, catalyst concentration and the duration. Maximum adipic acid product selectivity (77%) with about 85% cyclohexane conversion was attained at 100°C using catalyst: cyclohexane molar ratio 0·08. Under these conditions more than 80% cyclohexane was converted in the first hour, although selectivity to adipic acid continued to increase for the next 5 h. Cyclohexyl acetate and cyclohexyl monoadipate were identified as important intermediates. This study supports the mechanism proposed by Schultz, J. G. D. and Opchenko, A., J. Org. Chem., 38 (21) (1973) 3729. 相似文献