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以Ti(SO4)2和Zr(SO4)2为活性组分,以SiO2为载体,通过浸渍法制备复合固体酸催化剂Ti(SO4)2-Zr(SO4)2/SiO2。采用TG、酸量分析、FT-IR、XRD等方法对催化剂进行表征,考察焙烧温度、活性组分负载量对催化剂性能的影响。结果表明,催化剂制备的适宜条件为:焙烧温度300℃、焙烧时间3h、活性组分负载量50%。将制备的催化剂用于油酸甲酯的合成反应,在催化剂用量20g/mol、醇酸摩尔比4、反应时间5h、反应温度85℃的条件下,酯化率达到95.6%。催化剂的重复使用性能考察结果表明,在不经处理的条件下连续使用5次后,酯化率下降到80%以下。对失活催化剂的红外光谱分析结果表明,积炭是催化剂失活的主要原因,可通过焙烧、补充活性组分恢复其催化性能。
The composite solid acid catalyst Ti (SO4) 2-Zr (SO4) 2 / SiO2 was prepared by impregnation method with Ti (SO4) 2 and Zr (SO4) 2 as active components and SiO2 as carrier. The catalysts were characterized by TG, acid analysis, FT-IR and XRD. The effect of calcination temperature and active component loading on the catalyst performance was investigated. The results show that the optimum conditions for the preparation of catalyst are as follows: the calcination temperature is 300 ℃, the calcination time is 3h and the loading of active component is 50%. The prepared catalyst was used in the synthesis of methyl oleate. Under the conditions of the catalyst amount of 20g / mol, molar ratio of alkyd 4, reaction time 5h and reaction temperature 85 ℃, the esterification rate reached 95.6%. The reusable catalyst performance study results show that the esterification rate dropped to below 80% after 5 consecutive uses without treatment. Infrared spectrum analysis of the deactivated catalyst showed that carbon deposition was the main reason for the deactivation of the catalyst, which could be restored by roasting and supplementing the active components.