复合固体超强酸S_2O_8~(2-)/Fe_2O_3-CoO催化合成乙酸苄酯

以硫酸铁和硝酸钴为主要原料,采用沉淀-浸渍法制备新型固体超强酸催化剂S2O82-/Fe2O3-CoO,并用于乙酸苄酯的合成反应.该催化剂制备的最优条件为:焙烧温度为500℃,(NH4)2S2O8浸渍浓度0.5 mol/L,焙烧时间为2.5 h.采用该催化剂通过正交试验得到合成乙酸苄酯的最佳条件为:n(苄醇)?n(乙酸)=1.3?1.0,催化剂用量为0.6 g(以0.2 mol乙酸为准),带水剂环己烷用量为12 ml,反应时间为2.5 h,其酯化率可达98%以上.该催化剂具有催化活性高、不污染环境、可重复使用等特点.

Synthesis of Benzyl Acetate by the Composite Solid Superacid Catalyst S_2O_8~(2-)/Fe_2O_3-CoO

The novel composite solid superacid catalyst S_2O~(2-)_8/Fe_2O_3-CoO was prepared by Fe_2(SO_4)_3 and Co(NO_3)_2 as the raw material with coprecipitation-impregnation method,and it was used in the synthesis of benzyl acetate.The optimum conditions of catalyst preparation were: calcination temperature 500 ℃,impregnation concentration of ammonium peroxodisulfate 0.5 mol/L,calcination time 2.5 h.Based on the orthogonal experiment,the optimum synthetic conditions of benzyl acetate were resulted as follows: the molar ratio of benzyl alcohol to acetic acid was 1.3︰1.0,mass of the catalyst was 0.6 g(when acetic acid was 0.2 mol),the volume of the water removing reagent cyclohexane was 12 ml,and the reaction time was 2.5 h.The yield of esterification was more than 98% under above conditions.The novel type of catalyst S_2O~(2-)_8/Fe_2O_3-CoO has the features of highly activated,non-polluting and reusable.