钨酸催化氧化环己醇合成己二酸

Tungstic acid-catalyzed oxidation of cyclohexanol to adipic acid

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%。

The catalyzed oxidation of cyclohexanol with 30% aqueous hydrogen peroxide by mass fraction to produce adipic acid can be achieved using tungstic acid-acidic additive catalyst system in the absence of organic solvents and phase-transfer reagent. The results showed that the tungstic acid-sulfosalicylic acid catalyst system had the best catalytic effect among acidic additives when the tungstic acid amount was 2.5 mmol and the mole ratio of tungstic acid, acidic additive, cyclohexanol and hydrogen peroxide was 1 ： 1 ： 40 ： 176; and the yield and purity of adipic acid were 87.8% and 99.9% using sulfosalicylic acid catalyst sys- tem after 8-h reaction, respectively. The yield and purity of adipic acid were 65.6% and 97.3% , respectively, while using tungstic acid alone as a catalyst. And the yield of adipic acid was above 80% using phenol-weakly acidic compound as additives and was up to 81.5% when the tungstic acid-sulfosalicylic acid catalyst system was recycled 5 times.