Deep adsorptive desulfurization over Cu, Ce bimetal ion-exchanged Y-typed molecule sieve

In this paper, Ce(IV)-Y, Cu(II)-Y and Cu(II)-Ce(IV)-Y adsorbents were prepared by the liquid-phase ion-exchange Y zeolites with combined Cu and Ce ions at low temperature and room pressure. The adsorbents were characterized by means of X-ray diffraction, N-2-adsorption specific surface area measurements (BET), X-ray photoelectron spectroscopy, Pyridine adsorption infrared spectroscopy and Fourier transform infrared. The adsorptive desulfurization properties of these three adsorbents were studied in a fixed-bed unit through a model gasoline which made up of 1-octane solution of the refractory sulfur compounds (Such as thiophene and benzothiophene) and a certain amount of toluene or cyclohexene. The results indicate that Cu(II)-Ce(IV)-Y bind the organic sulfur compounds through two types of adsorption modes: pcomplexation and direct sulfur-adsorbent interaction. The adsorption selectivity of sulfur compounds onto Cu(II)-Ce(IV)-Y decreased in the order: benzothiophene > 2,5-dimethylthiophene > 3-methylthiophene > thiophene. The effect of competition components on the metal ion-exchanged Y zeolites for sulfur removal in the order: cyclohexene > toluene. The Cu(II)-Ce(IV)-Y possesses the high sulfur adsorption capacity similar to Cu(II)-Y and high selectivity for sulfur compounds similar to Ce(IV)-Y, which can be attributed to the synergistic interaction between Cu2+ and Ce4+.