固体碱催化剂Ru-MgZr催化制备共轭亚油酸的研究

Preparation of Conjugated Linoleic Acid over Ru-MgZr Solid Base Catalysts

采用水热法制备了Ru-Mg Zr固体碱催化剂,通过XRD、XRF和CO2-TPD等方法对催化剂进行表征。结果显示,镁离子进入Zr O2晶格中形成固溶体,生成了新的碱性位点。试验结果表明,Ru-Mg Zr固体碱作为多相催化剂在亚油酸异构化反应中表现出良好的催化性能。在镁锆摩尔比为4∶1,催化剂用量为0.2 g,反应温度为180℃,反应时间为1.5 h的条件下,亚油酸的转化率达到65.09%。此外,催化剂重复使用5次后,没有明显的活性损失。通过气相色谱分析表明,产物主要为共轭亚油酸,其中以具有生物活性的9c,11t-CLA、10t,12c-CLA和9t,11t-CLA 3种异构体为主。

Ru -MgZr solid base catalyst was prepared by hydrothermal method. The catalyst was characterized by XRD, XRF and CO2 - TPD. The characterization reveals that the Ru - MgZr catalysts generated new basic sites, which may be due to magnesium entering ZrO2 lattice to form a solid solution. Results showed that Ru - MgZr solid base as a heterogeneous catalyst exhibited excellent catalytic activity in the isomerization reaction of linoleie acid. Optimal conditions were as follows： the Mg/Zr molar ratio was 4： 1, catalyst dosage was 0.2 g, reaction temperature was 180 ℃ and reaction time was 1.5 h. At these conditions, the conversion of linoleic acid could reach 65.09%. Additionally, the catalyst can be recycled and reused for 5 times without a significant loss of catalytic activity. The molecular structures of CLA preparations were determined by GC, the biologically active isomers 9c, lit -CLA, 10t, 12c - CLA and 9t, llt - CLA, were the main products.