聚甲醛二甲醚合成反应中离子液体催化性能的比较

聚甲醛二甲醚是世界公认的环保型燃油添加剂，极具应用前景。为了研究离子液体阴阳离子对甲醇(MeOH)与三聚甲醛(TOX)合成聚甲醛二甲醚反应的影响，本文采用不同的离子液体进行催化反应。在温度120℃、釜压2.0 MPa、原料摩尔比(n_MeOH/n_TOX)2∶1、催化剂用量2.1%(质量)、反应时间4 h的反应条件下，探讨了离子液体阴阳离子结构对反应性能的影响，通过聚甲醛二甲醚选择性大小的比较，得出了不同离子液体的催化活性顺序。由不同离子液体阴、阳离子的催化活性顺序得出离子液体阴阳离子协同催化甲醇与三聚甲醛合成聚甲醛二甲醚的反应。

Comparison of catalytic properties of ionic liquids in polyoxymethylene dimethyl ethers synthesis reaction

Polyoxymethylene dimethyl ethers are world recognized environmentally benign fuel additives, and have great application prospect. In order to study the effects of anion and cation of ionic liquids on that methanol and trioxane synthesis polyoxymethylene dimethyl ethers reaction, 12 kinds of ionic liquids were used as catalyst. The structure of anion and cation of ionic liquids on the effects of reaction performance was discussed under the optimized reaction condition, which were the reaction temperature of 120℃, reactor pressure of 2.0 MPa, raw material mole ratio of 2∶1, catalyst dosage of 2.1%(mass), reaction time 4 h. Under these conditions, the catalytic activity order of anion and cation was obtained by comparing the polyoxymethylene dimethyl ethers selectivity. It was concluded that catalytic effects of ionic liquids was not a simple single anion or single cation at work, but the result of the anionic and cationic concerted catalysis.