Study on preparation and characteristics of AgCeY zeolites

Adsorbents were successfully prepared by the liquid-phase ion-exchange Y zeolites with Ag, Ce and combined Ag-Ce metal ions.The adsorbents were characterized by the X-ray diffraction (XRD), UV-vis diffuse reflectance (UV-vis), N₂-adsorption specific surface area measurements (BET), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), X-ray photoelectron spectrum analysis (XPS) and Fourier transform infrared (FT-IR). With thiophene/benzothiophene/1-octane/toluene model oil as feedstock,the effect of preparation and adsorption conditions of AgCeY adsorbent on desulfurization and its recycling use performance were investigated. The results show that the Ag and Ce species which are loaded on AgCeY zeolite exist as Ag⁺ and Ce⁴⁺. AgCeY not only has the high sulfur adsorption capacity similar to AgY but also has the higher selectivity for sulfur compounds similar to CeY. And the adsorption affinity of AgCeY follows in the order: benzothiophene > thiophene. The AgCeY adsorbent exchanged the Ag⁺ first, then the Ce³⁺, with a Ce/Ag mole ratio of 2.5 for 24 h, at 500 ℃ exhibited the best performance. With oil 20 mL, AgCeY 0.2 g, at 50 ℃ adsorbed for 60 min, the TP and BT uptake reach 59.0% and 96.5%, respectively.