DMF-Mediated Diffusion Regulation in Pyridine-Carboxylate Metal-Organic Frameworks Enables Efficient CHF₃ Capture

The development of efficient, stable, and easily scalable adsorbents, which are designed for the recovery of high-purity trifluoromethane (CHF₃) from industrial waste gas, faces significant challenges. Here, we present a solvent-docking strategy for synthesizing a new metal-organic framework, PAIF-101 (Pyridine-carboxylic acid-based frameworks). This approach utilizes DMF molecular coordination to achieve sub-angstrom precision in pore-aperture tuning while simultaneously generating additional adsorption sites. The two methyl groups on the DMF molecule function like molecular vises, firmly anchoring CHF₃ and achieving benchmark CHF₃/N₂ separation. PAIF-101 shows the highest reported CHF₃ uptake (3.54 mmol g^-1) to date, pronounced affinity at low pressures, and exceptional IAST selectivity (140). Density functional theory (DFT) calculations and molecular dynamics (MD) simulations revealed that modified DMF molecules within the pores play a crucial role in enhancing performance. Breakthrough experiments validate practical feasibility, producing high-purity (≥ 99.5%) CHF₃ with a productivity of 1.53 mmol g^-1 and sustaining excellent separation even at 60%RH. Notably, PAIF-101 can be rapidly synthesized in scalable quantities via a simple reflux method, yielding around 5 grams per batch. Taken together, the outstanding separation performance, robust stability, and scalable synthesis of PAIF-101 demonstrate its great potential for this challenging industrial separation.