离子液体中甲苯羰基化反应的探索研究

STUDY ON CARBONYLZATION OF TOLUENE IN CHLOROALUMINATE IONIC LIQUID

研究了以新型催化材料氯铝酸型离子液体(IL)为催化剂,催化甲苯羰基化反应合成对甲基苯甲醛的工艺过程。合成、改性得到多种类型的IL,考察不同IL催化甲苯羰基化反应规律。氯铝酸离子液体中甲苯羰基化反应的催化活性物种为Al2Cl7-,B酸改性的IL-I/2.0的催化活性有所提高,其中HCl改性效果最好,相同条件下甲苯转化率由改性前的26.5%提高到41.7%。以叔胺盐为阳离子中间体合成的B-L复合酸离子液体的催化活性明显高于IL-I,其中IL-T的催化活性最高。在离子液体/甲苯摩尔比为2.8、CO分压3.0MPa、反应温度40℃、反应1h的条件下,甲苯转化率达到56.4%,对甲基苯甲醛选择性为88.0%,进一步延长反应时间,甲苯的转化率可达80%以上。B-L复合酸离子液体催化剂用于甲苯羰基化反应,可使反应在较温和的条件下进行,并达到了较理想的甲苯转化率和对甲基苯甲醛选择性。

Process for the synthesis of para-tolualdehyde （PTAL） via carbonylization of toluene with CO catalyzed by chloroaluminate （ Ⅲ ） type of ionic liquids （ILs） was investigated. Carbonylization reaction of toluene in ILs was tested. The results indicate Al2Cl）- is the catalytic active species and the conversion of toluene increases with increasing the amount of IL used, raising reaction temperature, prolonging reaction time, or enhancing the partial pressure of CO. The ionic liquid modified by both metallic cation and Bronsted acid can improve the activity for the reaction. Furthermore, trialkylamini- urn-contained ILs with B-L complex acid such as IL-T IL-E and IL-P were prepared and firstly used in the reaction. It is found that their activity are much higher than IL-I, and IL-T who has the highest activity is the best catalyst for the reaction. Under the conditions of an IL/toluene molar ratio of 2.8, a CO pressure of 3.0 MPa, a temperature of 40℃, a reaction time of 1 h, conversion of toluene can be up to 56.4%.