微孔Noria聚合物用于二甲苯异构体吸附分离研究

二甲苯异构体的分离是一个非常重要但极具挑战性的工业过程,新型吸附剂材料的开发是实现其高效分离的关键。采用Noria和2,3,5,6-四氟对苯二腈制备了具有高比表面积的微孔Noria聚合物(MNP),并研究了MNP对二甲苯异构体的吸附分离能力。单组分二甲苯异构体在MNP上的吸附动力学及吸附等温线表明,MNP具有邻二甲苯优先吸附能力,Langmuir吸附等温线拟合得到邻二甲苯最大吸附量达344 mg·g-1。竞争吸附实验也表明MNP是一种邻二甲苯选择性吸附剂,邻二甲苯与间二甲苯的选择性最高可达2.4,邻二甲苯与对二甲苯选择性在1.9左右。动态穿透实验验证了MNP可以有效分离出邻二甲苯。此外,MNP具有极短的吸附平衡时间和优异的热稳定性,是一种具有潜力的邻二甲苯分离吸附剂。

Synthesis of high-crystallinity MIL-125 with outstanding xylene isomer separation performance

MIL-125 is a metal-organic framework with great potential for the adsorption and separation of xylene isomers.However,MIL-125 is usually synthesized under anhydrous and anaerobic conditions.In this study,homogeneously shaped and highly crystalline MIL-125 was synthesized by introducing water-resistant titanium-containing oligomers into the synthesis process.With the assistance of the novel oligomers,MIL-125 can be synthesized in the presence of water,which meets batch-production requirements.The adsorption separation performance of the obtained highly crystalline MIL-125 was also significantly enhanced.The para-xylene/meta-xylene selectivity can reach 13.5 in mesitylene,which is higher than the selectivity values of most previously reported para-selective adsorbents.The MIL-125 xylene separation performance was verified using both batch adsorption and breakthrough experiments in the liquid phase.In addition,the influence of the solvent effect was evaluated through microcalorimetric experiments,liquid-phase adsorption experiments,and theoretical calculations.