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以(NH4)2S2O8溶液为浸渍溶液,采用溶胶-凝胶法制备了添加稀土Sm元素的固体酸催化剂S_2O_2-8/SnO_2-Fe_2O_3-Sm_2O_3,采用FT-IR、XRD、TG-DTA等分析方法对催化剂进行表征。将催化剂应用于乙酸正丁酯的合成反应,考察了铁锡元素摩尔比、浸渍液浓度、焙烧温度、焙烧时间和稀土含量等条件对固体酸催化性能的影响,得到催化剂的最佳制备条件为:铁锡元素摩尔比为1∶4,(NH4)2S2O8浸渍液浓度为2.0 mol/L,焙烧温度为500℃,焙烧时间为2.5 h,添加稀土氧化钐含量为3%,乙酸正丁酯的酯化率最高达98%以上。添加稀土Sm元素的催化剂稳定性能良好,再生实验表明催化剂结焦及S_2O_2-8基团的流失是催化剂失活的主要原因。
The solid acid catalyst S_2O_2-8 / SnO_2-Fe_2O_3-Sm_2O_3 with rare earth element Sm was prepared by sol-gel method using (NH4) 2S2O8 solution as the impregnation solution. The FT-IR, XRD and TG- The catalyst was characterized. The catalyst was applied to the synthesis of n-butyl acetate. The effects of iron-tin molar ratio, impregnation solution concentration, calcination temperature, calcination time and rare earth content on the catalytic performance of solid acid were investigated. The optimum preparation conditions for the catalyst were : Iron-tin elemental molar ratio of 1: 4, (NH4) 2S2O8 impregnation solution concentration of 2.0 mol / L, calcination temperature of 500 ℃, calcination time was 2.5 h, adding rare earth samarium oxide content of 3%, n-butyl acetate Esterification rate up to 98%. The addition of rare earth Sm element of the catalyst stability is good, regeneration experiments show that the catalyst coking and S 2 O 2 - 8 group loss is the main reason for catalyst deactivation.