固体酸催化剂SO_4^(2-)/C-TiO_2-CeO_2的制备与表征

Preparation and Characterization of Solid Acid Catalyst SO_4^(2-)/C-TiO_2-CeO_2

用高温磺化法制得复合型稀土改性固体酸催化剂SO_4^(2-)/C-TiO_2-CeO_2,以油酸和甲醇的酯化反应为探针反应,考察了稀土氧化物CeO_2的质量分数、磺化温度、磺化时间对催化剂SO_4^(2-)/C-TiO2-CeO2催化活性的影响。催化剂SO_4^(2-)/C-TiO_2-CeO_2的最佳制备条件为:CeO_2的质量分数为2%(以活性炭质量计)、磺化温度为200℃、磺化时间为10h。该条件下制备的催化剂用于催化油酸与甲醇的酯化反应,酯化率可达到94.78%。利用FTIR、XRD、SEM、DTG、XRF对固体酸催化剂进行了表征,结果表明:稀土氧化物CeO_2和金属氧化物TiO_2共同作用可固化SO_4^(2-),并与SO_4^(2-)形成配位结构,增强了固体酸催化剂的催化性能并提高了其热稳定性。

Complex rare earth solid acid catalysts SO4^2-/C-TiO2-CeO2 were prepared by high temperature sulfonation method.Catalytic activity was also evaluated with esterification of oleic acid and methanol as a probe reaction.Further,the influences of mass fraction of CeO2,sulfonation temperature and sulfonation time on performance of the prepared catalyst were investigated.The results showed that catalyst SO4^2-/CTiO2-CeO2 exhibited a good catalytic activity when mass fraction of CeO2 was 2%（based on mass of activated carbon）,sulfonation temperature was 200 ℃ and sulfonation time was 10 h.The esterification rate of oleic acid and methanol could reach 94.78%,using the catalyst achieved under the best condition.FTIR,XRD,SEM,DTG,and XRF were used to characterize the prepared catalysts.As a result,the coordination structure of CeO2,TiO2 and SO4^2-can improve catalytic activity and thermal stability of catalyst SO4^2-/C-TiO2-CeO2.