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以硫酸锰和硝酸镧为原料,采用共沉淀-浸渍法制备不同比例的SO~(2-)_4/MnO_2/La~(3+)。以催化合成乙酸苄酯为探针反应,考察H_2SO_4浓度、La(NO_3)_3的质量分数、焙烧温度、焙烧时间等因素对其催化活性的影响。结果表明,催化剂制备的最佳条件为:硝酸镧的加人为硫酸锰的3%(质量分数),浸渍浓度为1 mol·L~(-1)的H_2SO_4,焙烧温度为450℃,焙烧时间3 h,酯化率到达最大,为89.7%。
Different proportions of SO 2 -, MnO 2 and La 3+ were prepared by coprecipitation - impregnation method using manganese sulfate and lanthanum nitrate as raw materials. Catalytic synthesis of benzyl acetate was used as the probe reaction. The effects of H 2 SO 4 concentration, mass fraction of La (NO 3) 3, calcination temperature and calcination time on the catalytic activity were investigated. The results show that the optimal conditions for the preparation of catalyst are as follows: the addition of lanthanum nitrate is 3% (mass fraction) of manganese sulfate, the concentration of H 2 SO 4 is 1 mol·L -1, the calcination temperature is 450 ℃, the calcination time is 3 h, esterification rate reached the maximum, 89.7%.