FeCl_3-Al(i-Bu)_3-phen胶体催化剂制备方法对催化活性的影响

研究了 Fe Cl3- Al( i- Bu) 3- phen胶体催化剂各组分的配比、加入顺序、陈化等制备方式影响催化活性的原因。在加氢汽油介质中 ,较佳 [Al]/[Fe]比值 ,能将 Fe Cl3颗粒表面的 Fe3+ 还原成 Fe2 + ,又与 Al( i- Bu) 3形成双电层使胶粒稳定。较佳的 [phen]/[Fe]比值保证有充分的 phen与 Fe2 +生成稳定的配合物 ,阻止 Al( i- Bu) 3将 Fe2 +还原成低价态 ( Fe+ ,Fe0 ) ,同时较佳配比制得的胶体催化剂颗粒小而均匀。因为生成活性位的反应是快速反应 ,只有 phen、Fe Cl3先于 Al( i- Bu) 3加入 ,才能有效阻止深度还原。所以最好的加料顺序是 phen+ Fe Cl3+ Al( i- Bu) 3;由于本体系是较稳定的胶体体系 ,在陈化时间为 4h、陈化温度在 - 1 5℃～ 2 0℃范围内几乎不影响催化剂活性。因为丁二烯聚合物能增加胶粒的稳定性 ,所以加丁二烯陈化优于不加丁二烯陈化

Effects of the Preparation Method of FeCl_3-Al(i-Bu)_3-Phen Colloid System on Its Catalytic Activity

The preparation method, such as the ratio, sequence of adding material and aging, affected the catalytic. The optimun ratio of / in hydro gasoline solution reduced Fe 3+ lying on the surface of particle to Fe 2+ , and provided colloid particles with ample Al(i Bu) 3 for making colloid particles stable. The optimum ratio of / make it possible that phen and Fe 2+ to form stable complex, which prevented Al(i Bu) 3 from reducing Fe 2+ to lower valence. And the catalyst prepared with the optimum ratio was small sized and even dispersed. Because the reaction forming the active site was quick, phen and FeCl 3 were added before Al(i Bu) 3 to prevent Fe 3+ from reducing to lower valence. So the best order of adding material was phen+FeCl 3+Al(i Bu) 3. As the system was stable, its catalytic activity was hardly affected by being aged for 4h and at the temperature from 15 to 20 ℃. The polymer of butadiene strengthened the stability of colloid particle, so aging with butadiene added was preferable.