Leveraging Surface Polarity in a Cost‐Effective Metal–Organic Framework for Olefin Purification From Methanol‐to‐Olefin Products

Abstract Research over the years has revealed the immense potential of metal–organic frameworks (MOFs) for purifying olefins such as ethylene (C₂H₄) and propylene (C₃H₆). 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 C₂H₄ and C₃H₆ 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 C₃H₆ and ethane (C₂H₆) compared to C₂H₄, 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 C₃H₆ and C₂H₆, confirming their preferential adsorption over C₂H₄. Breakthrough experiments demonstrate that JNU‐74a can efficiently produce polymer‐grade C₂H₄ (≥99.95%) and C₃H₆ (≥99.5%) from C₂H₆/C₂H₄, C₃H₆/C₂H₄, and C₃H₆/C₂H₆/C₂H₄ 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.