La^(3+)/CNMS-SO3H固体酸的制备及其催化合成正龙脑的研究

Preparation of La^(3+)/CNMS-SO_(3)H solid acid and study on its application in catalytic synthesis of Borneol

采用溶胶-凝胶法和浸渍法制备了La^(3+)/CNMS-SO_(3)H固体酸催化剂催化剂的优化工艺为:La^(3+)浓度为0.021 mol/L、硫酸浸渍浓度为2 mol/L、煆温度为500℃;通过BET、NH3-TPD、Py-FTIR等对催化剂的性质与结构进行表征。探究了单因素对α-蒎烯转化率及正龙脑收率的影响,结果表明,烯酸摩尔比为1:0.5、La^(3+)/CNMS-SO_(3)H质量为松节油质量的8%、温度为100℃、时间为8 h时,正龙脑的收率最高为40.83%,α-蒎烯转化率为100%;催化剂在重复使用6次之后,转化率仍在99%之上,龙脑的收率下降3%。

La^(3+)/CNMS-SO_(3)H,a solid acid catalyst,is prepared by sol-gel method and impregnation method.Its properties and structure are characterized by BET,NH3-TPD,Py-FTIR,etc.The optimized preparation process for the catalyst is as follows:La^(3+) concentration is 0.021 mol·L-1,sulfuric acid impregnation concentration is 2 mol·L-1,and calcination temperature is at 500℃.Impacts of single factor on the conversion of α-pinene and the yield of borneol over the catalyst is explored.Results show that the highest yield of borneol can reach 40.83% and the conversion rate of apinene can achieve 100% when the molar ratio of α-pinene to oxalic acid is 1:0.5,the mass of La^(3+)/CAMS-SO_(3)H is 8%that of turpentine,temperature remains at 100℃,and reaction lasts for 8 h.After the catalyst has been used for 6 times,the conversion of α-pinene is still above 99%,and the yield of borneol drops by 3%.