Dual Identity Validation of a Robust MOF Membrane for Efficient Multiscenario CO₂ Separation

Abstract Robust high‐valence metal–organic framework (MOF) membranes for CO₂ separations show great promise for achieving carbon neutrality. Herein, the elegant fabrication of tetravalent zirconium Materials of Institute Lavoisier‐140A (MIL‐140A) membranes are pioneered and validated the intriguing dual role for both CO₂‐selective and CO₂‐rejective separations by combining structural regulation with the exploitation of the appropriate anisotropic ultramicropores. This inimitable separation ability of “hitting two targets with one arrow” with distinctive molecular size cut‐offs, which originated from the significant orientation transformation, enables the membranes to satisfy multiscenario CO₂ capture requirements. The preferred (h0h)‐oriented MIL‐140A membranes exhibit superior mixed CO₂/CH₄ separation capacities (a separation factor of ≈30), while the highly (200)‐oriented MIL‐140A membranes exhibit remarkable mixed H₂/CO₂ separation capacities (a separation factor of ≈540), and they both ranked at the top among the present MOF membranes. This work highlights the promising prospects of the fresh MIL‐140 series for a given membrane‐based multiscenario CO₂ separation application through microstructure customization and manipulation.