摘要
本文以二氧化硅负载磷钨酸(H_3PW_(12)O_(40)/SiO_2)为催化剂,丁醛和乙二醇为原料合成丁醛乙二醇缩醛,探讨了H_3PW_(12)O_(40)/SiO_2/SiO_2对缩醛反应的催化活性,研究了醛醇物质的量比、催化剂用量、反应时间等因素对产物收率的影响。实验结果表明:H_3PW_(12)O_(40)/SiO_2/SiO_2是合成丁醛乙二醇缩醛的良好催化剂。在固定丁醛用量为0.2mol的情况下,n(丁醛):n(乙二醇)=1:1.4,催化剂的用量占反应物料总质量的1%,环已烷用量为4mL,反应时间为45min的条件下,产品收率可达77.6%。
A novel catalyst,H,PW_(12)O_(40)/SiO_2 was synthesized by a sol-gel technique,and characterized by FT-IR and XRD.Butyraldehyde glycol acetal was synthesized from butyraldehyde and glycol in the presence of H_3PW_(12)O_(40)/SiO_2as catalyst.The factors influencing the synthesis were discussed and the best reaction conditions were found out.Experimental results showed that H_3PW_(12)O_(40)/SiO_2 is an excellent catalyst.Under the experimental conditions of molar ratio of butyraldehyde to glycol is 1:1.4,the mass ratio of the catalyst is 1.0%of all the reactants,volume of cyclohexane is 4mL,and the reaction time is45 min,the yield of butyraldehyde glycol acetal can reach 77.6%.
