Synergistic Hydrophobic‐Polar Microenvironments in Corrugated Channels Enable Exceptional Moisture‐Tolerant CO 2 Capture

Overcoming the moisture sensitivity of porous adsorbents remains a critical challenge for industrial carbon capture, hindered by the inherent trade‐off between strong CO 2 affinity and competitive water adsorption. Here, we report a series of isostructural porous coordination polymers (PCP‐H, PCP‐NH 2 , and PCP‐OH) that realize corrugated channels where confined hydrophobic parallel aromatic walls and tunable isolated polar sites cooperate to form clip‐like traps for moisture‐tolerant CO 2 capture. PCP‐NH 2 is presented as the demonstration that achieves an exceptional CO 2 /N 2 selectivity, significantly outperforming its non‐functionalized and hydroxylated analogues despite identical framework topologies. Critically, PCP‐NH 2 integrates excellent CO 2 breakthrough performance with exceptional moisture tolerance (retained 95% capacity at 70%RH, even with trace SO 2 present) and stable performance over 99 cycles with fast kinetics under simulated flue gas conditions. In situ single‐crystal x‐ray diffraction and diffuse reflectance infrared Fourier transform spectroscopy, together with grand canonical Monte Carlo simulations, reveal that CO 2 molecules are stabilized through cooperative C═O···H and π···π interactions within the clip‐like traps, while hydrophobic channel surfaces and spatially separated polar sites suppress H 2 O uptake and preserve CO 2 selectivity at high humidity. These findings reveal a general design principle whereby synergistic hydrophobic–polar microenvironments reconcile strong target binding with hydrolytic robustness for challenging gas separations.