节点文献
柠檬酸对钨酸及磷钨酸的催化活性的改进
Phosphotungstic Acid or Tungstic Acid-Catalyzed Oxidation of Cyclohexanone to Adipic Acid in the Presence of Citric Acid
【摘要】 以磷钨酸/钨酸-柠檬酸为催化体系,在无有机溶剂和相转移剂的情况下,催化30%过氧化氢氧化环己酮合成己二酸。当磷钨酸∶柠檬酸∶环己酮∶过氧化氢=1∶20∶400∶200(0物质的量比,磷钨酸用量为0.25mmol)时,使用柠檬酸来调节钨酸催化活性,反应8h时,己二酸分离产率达81.2%、产品熔点为150 ̄153℃;以钨酸为催化剂,当钨酸∶柠檬酸∶环己酮∶过氧化氢=1∶2∶40∶200(物质的量比,钨酸用量为2.5mmol)时,反应8h,己二酸分离产率只有82.5%、产品熔点为150 ̄153℃。反应时间在2 ̄8h内,随反应时间的延长,己二酸分离产率增大,而8h后略有下降。
【Abstract】 Without organic solvent and phase-transfer reagent,the catalytic oxidation of cyclohexanone to adipic acid with aqueous 30% hydrogen peroxide can be achieved in the presence of phosphotungstic acid or tungstic acid-citric acid.When the molar ratio of phosphotungstic acid ∶ citric acid ∶ cyclohexanone ∶ hydrogen peroxide is 1∶20∶400∶2000(phosphotungstic acid,0.25 mmol),the isolated yield of adipic acid is up to 81.2% for 8 hs.If the tungstic acid is used as catalyst when the molar ratio of tungstic acid : citric acid ∶ cyclohexanone ∶ hydrogen peroxide is 1∶2∶40∶200(phosphotungstic acid,2.5 mmol),the isolated yield of adipic acid is 82.5% and the purity of product is high.During the reaction time of 2~8 hs,the yield of adipic acid increased with reaction time prolonged.After 8 hours,the yield of adipic acid decreased with time increased little by little.
【Key words】 cyclohexanone; hydrogen peroxide; phosphotungstic acid; tungstic acid; adipic acid; citric acid;
- 【文献出处】 中国钨业 ,China Tungsten Industry , 编辑部邮箱 ,2006年03期
- 【分类号】O643.36
- 【下载频次】129