Linker micro-regulation of a Hofmann-based metal-organic framework for efficient propylene/propane separation

Fabricating easily available adsorbents with highly selective adsorption separation performance for propylene/propane mixtures is a desirable and energy-efficient way to produce high-purity propylene in the petrochemical industry. In this study, through ligand micro-regulation to optimize the pore environment, an inexpensive Hofmann-based metal-organic framework (CoNi-piz) with sandwich-like one-dimensional channels decorated with multiple open metal sites has been prepared by a direct mixing method under ambient conditions for propylene/propane separation. This newly synthesized porous material exhibits not only excellent selectivity (>100) for an equimolar propylene/propane mixture (50 : 50, v/v) but also a larger uptake ratio (11.3) at low pressure compared to the previously studied adsorbents, thus facilitating efficient propylene/propane separation under ambient conditions. Its adsorption separation performance has been validated by single-component adsorption isotherms, IAST selectivity calculations, and dynamic breakthrough experiments. Moreover, advantages such as inexpensive raw materials, a readily scalable synthesis process, and excellent reusability together make the described material highly promising for propylene/propane separation to afford high-purity propylene in industrial settings.