Adsorptive removal of benzothiophene using porous copper-benzenetricarboxylate loaded with phosphotungstic acid

Liquid-phase adsorption of benzothiophene (BT) over phosphotungstic acid (PWA)-loaded porous copper-benzenetricarboxylate (Cu-BTC, one of the porous metal-organic frameworks) has been studied to understand the effect of PWAs on the adsorption/removal. The maximum adsorption capacity (Q0) increases with increasing PWA loading up to a W/Cu (wt./wt.) ratio of 0.22 in PWA/Cu-BTCs, resulting in an increase in the Q0 by 26% compared with the virgin Cu-BTC. Since there is no remarkable change in the surface area and pore volume for the virgin and PWA loaded Cu-BTCs, it is suggested that the improved Q0 over PWA/Cu-BTCs is due to the favorable interactions like acid–base ones between the acidic PWA and slightly basic BT. Based on this result, it can be suggested that MOF (metal-organic framework)-type materials, modified suitably, can be used in the adsorptive desulfurization of fuels.