Synergistic Hydrophobic-Polar Microenvironments in Corrugated Channels Enable Exceptional Moisture-Tolerant CO2 Capture.

Overcoming the moisture sensitivity of porous adsorbents remains a critical challenge for industrial carbon capture, hindered by the inherent trade-off between strong CO2 affinity and competitive water adsorption. Here, we report a series of isostructural porous coordination polymers (PCP-H, PCP-NH2, 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 CO2 capture. PCP-NH2 is presented as the demonstration that achieves an exceptional CO2/N2 selectivity, significantly outperforming its non-functionalized and hydroxylated analogues despite identical framework topologies. Critically, PCP-NH2 integrates excellent CO2 breakthrough performance with exceptional moisture tolerance (retained 95% capacity at 70%RH, even with trace SO2 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 CO2 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 H2O uptake and preserve CO2 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.