Precise pore engineering of multivariate metal–organic frameworks for boosting hexane isomers separation

Abstract The adsorptive separation of hexane isomers is a critical yet challenging process in the petrochemical industry. In this study, a series of pillar‐layer MOF materials, CuCam‐Apyz/Dabco, were successfully synthesized using a multivariate metal–organic framework (MTV‐MOF) strategy, enabling systematic pore environment tuning by adjusting pillar ligand ratios. Among them, CuCam‐Apyz 0.48 Dabco 0.52 exhibited the most favorable sieving performance for hexane isomers. This material selectively adsorbed n‐hexane (nHEX, 1.83 mmol/g) and 3‐methylpentane (3MP, 1.41 mmol/g), while nearly excluding 2,2‐Dimethylbutane (22DMB, 0.04 mmol/g). The resulting uptake ratios of nHEX/22DMB and 3MP/22DMB mixtures reached 46.9 and 35.3, respectively, exceeding those reported for most MOFs to date. Density functional theory (DFT) calculations further elucidated the nature of host‐guest interactions and revealed distinct diffusion energy barriers and binding energies among the isomers, confirming a size‐exclusion‐based separation mechanism. Additionally, breakthrough experiments and stability tests validated its efficiency and robustness, highlighting its potential for industrial hexane isomer separation.