固体超强酸SO_4^(2-)/TiO_2催化合成乙酸苯酯

Synthesis of phenyl acetate catalyzed by solid superacid SO_4^(2_)/TiO_2

以沉淀法制备了SO_4^(2-)/TiO_2和SO_4^(2-)/ZrO_2固体超强酸,采用Hammett指示剂对催化剂进行了表征。比较了不同催化剂对乙酸酐与苯酚直接酯化合成乙酸苯酯的催化活性,并考察了固体超强酸催化剂的制备条件及酯化反应条件对催化活性的影响。实验结果表明,SO_4^(2-)/TiO_2固体超强酸具有较高的催化活性,最佳合成条件:SO_4^(2-)/TiO_2于600 ℃焙烧4 h,固体超强酸SO_4^(2-)/TiO_2用量为原料总质量的3%,原料乙酸酐与苯酚物质的量比为1.05∶1.00,反应温度(140～150)℃,反应时间1.5 h,乙酸苯酯收率为98.0%。

SO_4^(2-)/TiO_2 and SO_4^(2-)/ZrO_2 solid superacid catalysts were prepared by precipitation method and characterized by means of Hammett indicator.Activity of the catalysts for synthesis of phenyl acetate via esterification of acetic anhydride and phenol was tested.Effects of solid superacid preparation and esterification reaction conditions on the esterification results were investigated.SO_4~2-/TiO_2 solid superacid exhibited superior activity to SO_4^(2-)/ZrO_2. Phenyl acetate yield of 98.0% was obtained over SO_4^(2-)/TiO_2 under the optimum condition as follows:calcination at 600℃ for 4 h,mass fraction of catalyst in the total mass of the feed = 3%,acetic-anhydride-to-phenol mole ratio of 1.05:1.00,reaction temperature (140-150) ℃,reaction time 1.5 h.