Programmed fluorine binding engineering in anion-pillared metal-organic framework for record trace acetylene capture from ethylene.

Porous physisorbents are attractive candidates for selective capture of trace gas or volatile compounds due to their low energy footprints. However, many physisorbents suffer from insufficient sorbate-sorbent interactions, resulting in low uptake or inadequate selectivity when gases are present at trace levels. Here, we report a strategy of programmed fluorine binding engineering in anion-pillared metal-organic frameworks to maximize CH binding affinity for benchmark trace CH capture from CH. A robust material (ZJU-300a) was elaborately designed to provide multiple-site fluorine binding model, resulting in an ultrastrong CH binding affinity. ZJU-300a exhibits a record-high CH uptake of 3.23 millimoles per gram (at 0.01 bar and 296 kelvin) and one of the highest CH/CH selectivity (1672). The adsorption binding of CH and CH was visualized by gas-loaded ZJU-300a structures. The separation capacity was confirmed by breakthrough experiments for 1/99 CH/CH mixtures, affording the maximal dynamic selectivity (264) and CH productivity of 436.7 millimoles per gram.