Low-temperature loading of Cu⁺ species over porous metal-organic frameworks (MOFs) and adsorptive desulfurization with Cu⁺-loaded MOFs

Porous metal-organic frameworks (MOFs, MIL-100-Fe, iron-benzenetricarboxylate) supported with Cu⁺ species were obtained for the first time under mild condition without high temperature calcinations. The Cu⁺-loaded MOFs were evaluated as efficient adsorbents for the liquid-phase adsorption of benzothiophene (BT). The effect of Cu⁺ loading on the adsorption kinetics and maximum adsorption capacity (Q₀) for the adsorption of BT was also studied. Q₀ increased with increasing copper loading up to a Cu/Fe (wt./wt.) ratio of 0.07 in Cu⁺-loaded-MIL-100-Fe, resulting in an increase in the Q₀ by 14% compared with the virgin MIL-100-Fe without Cu⁺ ions. Since the surface area and pore volume decrease with the loading of copper, the increased Q₀ over the Cu⁺-loaded MIL-100-Fe adsorbents suggests specific favorable interactions (probably by π-complexation) between Cu⁺ and BT.