Leveraging Surface Polarity in a Cost‐Effective Metal–Organic Framework for Olefin Purification From Methanol‐to‐Olefin Products
Gang‐Ding Wang, Yong‐Zhi Li, Heng Zeng, Lei Hou, Weigang Lu, Dan Li
Abstract
Abstract Research over the years has revealed the immense potential of metal–organic frameworks (MOFs) for purifying olefins such as ethylene (C 2 H 4 ) and propylene (C 3 H 6 ). However, many of these MOFs face challenges in terms of economic viability, particularly in production scalability, long‐term stability, and process capability. In this study, we present a low‐cost and easily scalable synthesis of a robust MOF material (JNU‐74a), featuring a balanced surface polarity that allows for one‐step C 2 H 4 and C 3 H 6 purification from methanol‐to‐olefin (MTO) products. By incorporating highly electronegative atoms on the nonpolar surface, JNU‐74a exhibits substantially larger absorption capacity and stronger binding affinity for C 3 H 6 and ethane (C 2 H 6 ) compared to C 2 H 4 , as evidenced by their gas adsorption isotherms and heats of adsorption measurements. In‐depth analyses through in situ single‐crystal X‐ray diffraction (SCXRD) of gas@JNU‐74a unveil multiple supramolecular bindings that favor C 3 H 6 and C 2 H 6 , confirming their preferential adsorption over C 2 H 4 . Breakthrough experiments demonstrate that JNU‐74a can efficiently produce polymer‐grade C 2 H 4 (≥99.95%) and C 3 H 6 (≥99.5%) from C 2 H 6 /C 2 H 4 , C 3 H 6 /C 2 H 4 , and C 3 H 6 /C 2 H 6 /C 2 H 4 mixtures of different ratios in a single adsorption‐desorption cycle. With its impressive separation capability, high chemical stability, and cost‐effective production, JNU‐74a holds promise for olefin purification from MTO products and other challenging industrial separations.