Engineering Supramolecular Binding Sites in a Chemically Stable Metal-Organic Framework for Simultaneous High C2H2 Storage and Separation

Developing porous materials to overcome the trade-off between adsorption capacity and selectivity for C2H2/CO2 separation remains a challenge. Herein, we report a stable HKUST-1-like MOF (ZJU-50a), featuring large cages decorated with high density of supramolecular binding sites to achieve both high C2H2 storage and selectivity. ZJU-50a exhibits one of the highest C2H2 storage capacity (192 cm(3) g(-1)) and concurrently high C2H2/CO2 selectivity (12) at 298 K and 1 bar. Single-crystal X-ray diffraction studies on gas-loaded ZJU-50a crystal unveil that the incorporated supramolecular binding sites can selectively take up C2H2 molecule but not CO2 to result in both high C2H2 storage and selectivity. Breakthrough experiments validated its separation performance for C2H2/CO2 mixtures, providing a high C2H2 recovery capacity of 84.2 L kg(-1) with 99.5 % purity. This study suggests a novel strategy of engineering supramolecular binding sites into MOFs to overcome the trade-off for this separation.

Automated summary

This study presents a novel strategy by engineering supramolecular binding sites into MOFs to achieve high C2H2 storage and selectivity, overcoming the trade-off in C2H2/CO2 separation. The developed MOF (ZJU-50a) exhibits one of the highest C2H2 storage capacities and selectivities, providing a promising solution for C2H2 recovery with high purity.