油酸支链化反应催化剂的改性

Modification of Catalysts for Synthesis of Branched-Chain Fatty Acids from Oleic Acid

在酸改性的镁碱沸石催化剂存在下,以油酸为原料,通过异构化和加氢反应合成饱和支链脂肪酸。采用XRD和BET方法对催化剂进行了表征,并采用1H NMR,FTIR,LC-MS方法对反应产物进行了表征。考察了质子交换酸的种类及浓度、质子交换的温度及时间对催化剂活性的影响,探索了改性镁碱沸石催化剂催化油酸异构化反应的机理。经单因素实验确定了最佳催化剂活性条件:选取盐酸为质子交换酸,盐酸浓度1.0 mol/L、质子交换温度55℃、质子交换时间12 h。在上述条件下改性的镁碱沸石催化剂存在下,饱和支链脂肪酸的收率可达79.85%。

K＋-ferrierite zeolite was modified with different acids.Saturated branched-chain fatty acids were synthesized from oleic acid by isomerization over the modified K＋-ferrierite zeolite catalysts and hydrogenation over active carbon supported Ni catalyst.The crystal,pore volume and specific surface area of the isomerization catalysts were characterized by means of XRD and BET.The synthesized products were analyzed by means of 1H NMR,FTIR and LC-MS.The influences of the acid types,acid concentration,modifying temperature and modifying time on the catalyst performances in the synthesis,and the reaction mechanism were investigated.The optimum modifying conditions were as follows：HCl as proton exchange source,HC1 concentration 1.0 mol/L,modifying temperature 55 ℃ and modifying time 12 h.The yield of saturated branched-chain fatty acids reached 79.85％ over the catalyst modified with 1.0 mol/L HCl.