Robust Zirconium Metal-Organic Framework Bearing Three-Dimensional Through-Space Channels and Shape-Persistent...

Carbon capture and storage (CCS) with solid physical adsorbents has long been considered as an energy-efficient approach to mitigate anthropogenic carbon dioxide emissions. The quest for efficient porous sorbents for short-term CO2 storage and transport is still ongoing, as current materials possess certain limitations in terms of capacity, selectivity, and stability. In this work, capitalizing on the highly modular metal-organic frameworks (MOFs), we designed and synthesized a highly porous and robust zirconium MOF (SJTU-520-Zr) by employing a tetratopic linker that bears a unique shape-persistent macrocycle moiety. This functional macrocycle unit serves as inherent CO2-philic apertures within a cubic topological framework featuring three-dimensional through-space channels, which collectively enable exceptional high-pressure CO2 capture and storage performance, achieving balanced gravimetric and volumetric capacities of 1.23 g g-1 and 0.56 g cm-3, respectively, at 25 bar and 298 K. This performance places SJTU-520-Zr among the top-tier sorbents for CO2 storage, yet distinguishes itself from those that rely solely on ultrahigh surface areas. Control experiments performed with SJTU-520-Y─a fragile isostructural MOF constructed from hexanuclear Y6 clusters─underscore that the exceptional performance relies critically on the preservation of 3D interconnected channels and unobstructed pore apertures. Contrast experiments combined with computational calculations unraveled a unique CO2-responsive "gate-opening" of the shape-persistent macrocycle unit driven by favorable π···π interactions, which facilitate thermodynamic CO2 access into the framework. This work, therefore, provides a blueprint for the rational design and synthesis of bespoke materials featuring shape-persistent functionality tailored for challenging applications.