Hydrophobic CHA-ZIFs with a junctional trap between cha and d6r cages for adsorption of 2,3-butanediol in aqueous solution

• Hydrophobic CHA-ZIFs with junctional traps between cha and d6r cages selectively adsorb 2,3-butanediol over 1,3-propanediol from dilute aqueous solutions. • ZIF-301 and ZIF-300, containing halogen groups, outperform ZIF-302 (methyl groups) in adsorptive separation performance. • ZIF-301 achieves an adsorption capacity of 116.4 mg·g−1 and a selectivity of 3.8 for 2,3-BDO/1,3-PDO in dynamic column adsorption. • Computational simulations confirm that 2,3-BDO preferentially binds in the junctional trap, highlighting the importance of hydrophobic and confined pore structures for diol separation.