Hexane isomers sorption on a functionalized metal-organic framework

A series of functionalized porous Zr terephthalate MOFs of the UiO-66(Zr) structure type bearing either Br, NH2 or NO2 groups have been synthesized at the multi-gram scale through an atmospheric pressure solvothermal route with the final aim of investigating the influence of functionalization on the separation of hexane isomers (22DMB, 23DMB, 3MP and nHEX). The studies performed in a fixed bed adsorption column with equimolar mixtures at temperatures between 343 and 423 K and partial pressure up to 10 kPa have shown that the Br, NO2 and NH3 forms exhibit an uptake reaching 15%, being the sorption selectivity hierarchy on the whole comparable to the bared UiO-66 solid: 22DMB approximate to 23DMB >> 3MP nHEX. The 22DMB/nHEX selectivity reaches approximately three at low uptake while the 22DMB/3MP selectivity of UiO-66_NO2 is nearly constant (1.3)