Supercritical Impregnation in Carboxylated Based MOFs.

Abstract

Metal-Organic Frameworks (MOFs) are porous materials made of metal clusters connected by organic linkers, typically dicarboxylate ligands. These materials have been intensively studied in recent years due to the distinctive properties such as high surface area, surface functionalization and structural flexibility for some of them. The potential applications are broad in fields such as catalysis, separations or drug delivery.[1] The supercritical CO2 (sc-CO2) has been recently used to activate MOFs, i.e. the removal of the excess of ligand and solvent from the pores, in substitution of procedures like calcination which can damage the crystallinity. Through this technology the highest surface area has been reported, around 7000 m2/g.[2] Therefore supercritical fluids seem to be of potential interest in MOFs processing. In our case we have tested the impregnation with supercritical CO2 in MOFs, in opposition to liquid impregnation which requires post processing steps, as separation and drying of the material.