Facile synthesis of Fe-based metal-organic frameworks from Fe₂O₃ nanoparticles and their application for CO₂/N₂...

A facile approach was employed to fabricate MIL-100(Fe) materials from Fe₂O₃ nanoparticles through a conventional hydrothermal reaction without the presence of HF and HNO₃. Effects of trimesic acid content in the reaction system on the quality and CO₂/N₂ 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@Fe₂O₃#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 m²·g^-1. At 25 °C and 1 bar, M-100Fe@Fe₂O₃#1.80 showed a CO₂ adsorption capacity of 1.10 mmol·g^-1 and an IAST-predicted CO₂/N₂ selectivity of 18, outperforming conventional adsorbents in CO₂/N₂ separation. Importantly, this route opens a new approach to utilizing Fe₂O₃-based waste materials from the iron and steel industry in manufacturing Fe-based MIL-100 materials.