A series of molecular sieve-immobilized Brønsted acidic ionic liquids ([email protected]) was prepared, characterized and utilized as efficient catalysts for the synthesis of polyoxymethylene dimethyl ethers (PODE_n or DMM_n) from methylal (DMM₁) and trioxane (TOX). Combined characterization results from fourier transform infrared (FT-IR) spectroscopy, elemental analysis, thermogravimetry (TG), N₂ adsorption-desorption (Brunauer-Emmett-Teller, BET) isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and temperature-programmed desorption of ammonia (NH₃-TPD), suggested that the synthesized BAILs were successfully immobilized on the surface of molecular sieves through covalent bonds. Moreover, the catalytic performance tests demonstrated that NaZSM-5 immobilized SO₃H-functionalized ionic liquids (ILs) i.e., [email protected], exhibited excellent activity for the acetalation of DMM₁ with TOX, compared to the homogeneous catalysis of the precursors ([MIMBs]HSO₄) as well as other molecular sieve-supported ILs. The influence of catalyst concentration, molar ratio of DMM₁ to HCHO, temperature and reaction duration on the catalytic activity were investigated by employing [NaZSM-5IMBs]HSO₄ as the catalyst. It was demonstrated that a superior conversion of formaldehyde (FA) (90.3%) and excellent selectivity for DMM_3-8 (53.5%) has been achieved in mild conditions (110 °C, 2.5 MPa for 2 h). Additionally, the catalyst can be effortlessly separated by filtration and reused more than ten times without significant loss of activity.

制备了一系列固定在分子筛上的布朗斯台德酸性离子液体（[已电子邮件保护]），并表征为由甲基（DMM ₁）和三恶烷（TOX）合成聚甲醛二甲醚（PODE _n或DMM _n）的有效催化剂。）。傅里叶变换红外（FT-IR）光谱，元素分析，热重分析（TG），N ₂吸附-解吸（Brunauer-Emmett-Teller，BET）等温线，X射线衍射（XRD），扫描电子显微镜（ SEM）和程序升温解吸的氨（NH ₃-TPD），表明合成的BAILs通过共价键成功地固定在分子筛表面。此外，催化性能测试表明，与前体的均相催化相比，NaZSM-5固定的SO ₃ H-官能化离子液体（ILs），即[受电子邮件保护]，对于用TOX进行DMM ₁缩醛化显示出优异的活性（ [MIMBs] HSO ₄）以及其他分子筛支持的IL。[NaZSM-5IMBs] HSO ₄研究了催化剂浓度，DMM ₁与HCHO的摩尔比，温度和反应时间对催化剂活性的影响。作为催化剂。结果表明，在温和的条件下（110°C，2.5 MPa，2 h），甲醛（FA）的转化率高（90.3％），对DMM _3-8的选择性高（53.5％）。另外，可以通过过滤毫不费力地分离催化剂，并重复使用十次以上，而没有明显的活性损失。