Robust Zirconium Metal–Organic Framework Bearing Three-Dimensional Through-Space Channels and Shape-Persistent CO2-Philic Apertures for Exceptional CO2 Capture and Storage

Abstract

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.