Bioinspired Adaptive Ångström‐Channels in a Hydrogen‐Bonded Metal–Organic Framework for Selective Water Removal From Gas Streams by Molecular Sieving Dehydration

The removal of water from light hydrocarbons is a critical yet energy‐intensive step in petrochemical processes. Conventional adsorbents often suffer from high regeneration temperatures and undesirable co‐adsorption. Inspired by the selective water transport mechanism of aquaporins, we report a hydrogen‐bonded metal–organic framework, ZNU‐33, featuring bioinspired adaptive one‐dimensional channels. The pore walls are decorated with both positively charged (Hbpa + ) and negatively charged (HEDP 4− ) recognition sites. Using in situ single‐crystal x‐ray diffraction, we captured five phases of ZNU‐33, activated (ZNU‐33‐α), intermediate (ZNU‐33‐β), partially dehydrated (ZNU‐33‐γ and ZNU‐33‐γ2), and fully hydrated ZNU‐33, directly visualizing a water‑triggered structural transition. Structural snapshots reveal water uptake proceeding from free‐channel water to Cu 2+ coordination and then to extended hydrogen‐bonded water chains. ZNU‐33 exhibits high water uptake (9.50 mmol/g at 2.85 kPa and 298 K) and negligible adsorption of CO 2 and all light hydrocarbons. Breakthrough experiments demonstrate efficient water removal under wide flow rates, temperatures, and humidity levels, with water‐adsorption capacity recoverable under substantially milder activation conditions than those required by the investigated conventional zeolites. This work not only provides a high‑performance material for selective dehydration, but also establishes a bioinspired adaptive adsorption mechanism for designing water‐selective adsorbents.