Shape‐based sieving of hexane isomers in liquid‐phase by a scalable metal–organic framework

The separation of mono‐ and di‐branched alkane isomers is an industrially important yet highly challenging process requiring precise pore structures. Here, we report a scalable metal–organic framework, Ni 3 (H 1.5 BTC) 2 (BTC)(DABCO) 3 (denoted as Ni‐HDB), featuring an anisotropic, “bat‐shaped” pore window that enables precise discrimination of the sterically similar 3‐methylpentane (3MP) and 2,3‐dimethylbutane (23DMB) pair (~0.3 Å difference in kinetic diameter), thereby enabling efficient separation of mono‐ and di‐branched isomers. Multicomponent vapor‐ and liquid‐phase experiments, supported by molecular simulations, reveal that separation arises from shape‐governed molecular accommodation rather than simple size exclusion. Notably, under industrially relevant liquid‐phase conditions, a packed column of pelleted Ni‐HDB directly produces a high‐octane gasoline fraction (RON > 91.5) from a five‐component alkane mixture, substantially exceeding the industrial benchmark of 83 for refined hexane mixtures. Combined with scalable synthesis, high stability, and low cost, this work establishes a practical, energy‐efficient route for liquid‐phase adsorptive upgrading of branched alkanes.