Facile synthesis of Fe-based metal-organic frameworks from FeO nanoparticles and their application for CO/N separation.

A facile approach was employed to fabricate MIL-100(Fe) materials from FeO nanoparticles through a conventional hydrothermal reaction without the presence of HF and HNO. Effects of trimesic acid content in the reaction system on the quality and CO/N separation performance of the as-prepared MIL-100(Fe) samples were investigated. Using 1.80 g of trimesic acid in the reaction system yielded the sample M-100Fe@FeO#1.80, which proved to be the optimal sample. This choice struck a balance between the amount of required trimesic acid and the quality of the resulting material, resulting in a high yield of 81% and an impressive BET surface area of 1365.4 m·g. At 25 °C and 1 bar, M-100Fe@FeO#1.80 showed a CO adsorption capacity of 1.10 mmol·g and an IAST-predicted CO/N selectivity of 18, outperforming conventional adsorbents in CO/N separation. Importantly, this route opens a new approach to utilizing FeO-based waste materials from the iron and steel industry in manufacturing Fe-based MIL-100 materials.