The removal of carbon dioxide (CO2) from natural gas is critical for pipeline integrity and downstream processing, yet it remains a challenging separation. While porous coordination polymers offer tunable platforms for this task, many frameworks sacrifice either high CO2 affinity or hydrolytic robustness. Here, we report the rational design and synthesis of NTU-77, a stable copper-based framework assembled from an asymmetric ligand integrating pyridine, imidazole, and carboxylate functionalities. This strategic design yields a material that synergistically combines a positive-charge framework, accessible open metal sites, a nitrogen-decorated polar pore surface, and robust coordination bonds. NTU-77 exhibits good moisture stability (3 months) and demonstrates promising CO2/CH4 separation performance at 298 K. Breakthrough simulations confirm its potential under mixed-gas conditions. This work highlights the effectiveness of asymmetric multifunctional ligands in constructing adsorbents that bridge the gap between high selectivity and practical stability for energy-efficient gas purification.
Yin et al. (Wed,) studied this question.