Construction of the π-complexation desulfurization adsorbent containing Cu+ at defective sites of UiO-66

Adsorption desulfurization is a very effective method to remove thiophenic compounds from fuels. The metal–organic frameworks (MOFs) have emerged as a new type of desulfurization adsorbents because of their porous nature and large specific surface area. In this study, Cu2+ was covalently introduced into the UiO-66 framework at the defective sites by the solvothermal method. Further, the π-complexation adsorbent UiO-66-Cu(I) containing Cu+ for adsorption desulfurization was synthesized by the methanol vapor-induced reduction. The adsorption performance was tested for the removal of thiophene from the model fuels with different sulfur concentrations. In comparison with the pristine UiO-66, the adsorbent UiO-66-Cu(I) has a higher adsorption capacity for thiophene, reaching 14.8 mg S/g. The competitive adsorption results indicated that UiO-66-Cu(I) has good selectivity for thiophene in the presence of aromatic compounds. From the recycling experiments, this adsorption still has the 86 % of the initial capacity after four cycles, indicating that the adsorbent has a good recycling performance.