Small. 2026 Jul 13:e74568. doi: 10.1002/smll.74568. Online ahead of print.
ABSTRACT
The low-cost C3H8/C3H6/C3H4 separation for high-grade C3H6 is of paramount importance but extremely difficult in the chemical industry. Here we report an economic strategy of functionalizing Zr-based metal-organic frameworks (MOFs) with amino acids for one-step C3H6 purification from ternary C3 mixtures. The resulting UiO-67-AA exhibits exceptionally high C3H8 and C3H4 uptakes and benchmark selectivities for C3H8/C3H6 and C3H4/C3H6 separations, rivaling reported ternary C3 separating MOFs. Breakthrough experiments confirm its excellent performance in producing high-purity C3H6 in one step. Crucially, the estimated over 2250 times the cost reduction among reported C3H8/C3H4-selective MOFs makes UiO-67-AA an ideal candidate for industrial C3H6 purification. In situ infrared spectroscopy, in situ neutron powder diffraction, and theoretical calculations indicate that amino acids offer selective binding to dually strengthen both C3H8 and C3H4 affinity over that of C3H6, with the amino group dictating the supramolecular interactions. Systematic evaluation across UiO-67 with diverse nitrogen moieties establishes a monotonic relationship between the separation performance and the specific nitrogen electronegativity, providing an element‑specific and quantitative electronegativity-driven design rule for next-generation MOF adsorbents for industrial olefin purification.
PMID:42439029 | DOI:10.1002/smll.74568