三聚甲醛与甲醇在SO42-/Fe2O3固体超强酸上的开环缩合反应研究

摘要

对SO42-/Fe2O3固体超强酸上三聚甲醛与甲醇开环缩合反应制备聚甲醛二甲基醚(DMMn)的反应条件进行了研究.其中,醇醛比、反应温度和反应时间对产物分布的影响较大.当甲醇与三聚甲醛的物质的量比(即醇醛比)为1.2、反应温度130℃、反应时间2h、反应压力0.1MPa、催化剂用量为总反应物质量的1.5％时,柴油添加组分DMM3-8收率可达22％,同时,SO42-/Fe2O3具有较好的循环使用性能.并运用XRD、SEM、NH3-TPD、IR等表征手段对反应前后催化剂进行了分析.%The ring-opening and condensation of trioxane with methanol over the SO42-/Fe2O3 solid superacid to synthesize polyoxymethylene dimethyl ethers (DMMn) were studied. The influences of the mole ratio of methanol to trioxane, temperature, pressure and reaction time on the catalytic performance of the catalysts were investigated. The results showed that under the optimum reaction conditions of methanol/trioxane mole ratio of 1.2, 130℃, 2h, 0.1 MPa and catalyst mass fraction of 1.5%, the yield of DMM3-8, which are the ideal additives for diesel fuel, could reach to 22%, and the catalyst had good reuse performance. XRD, SEM, NH3-TPD and FT-IR were used for the charecterization of the catalysts before and after reaction.