Insight into the relationship between effective active sites and ultra-deep adsorption desulfurization performance of CuCeY with different Cu precursors

Adsorption desulfurization processes employing zeolites as sorbents are considered to be prospective desulfurization methods owing to their cost-effectiveness.

Y zeolites modified with Cu and Ce have excellent adsorption capacity and selectivity for adsorption desulfurization. However, the effect of using different metal precursors on the active sites of these sorbents and their adsorption desulfurization performance still remains ambiguous, which impedes the development of improved desulfurization adsorbents. Herein, Cu(NO₃)₂, Cu(Ac)₂, and CuSO₄ were selected as Cu precursors to prepare a series of CuCeY from CeY zeolite. Desulfurization experimental results indicate that outstanding breakthrough adsorption capacities for thiophene (ca. 6.25 mg·g⁻¹) with benzene as the solvent were achieved by the CuCeY_A. The interaction between the CuCe metals was beneficial for enhancing the electron transfer between Cu²⁺+Ce³⁺/Ce⁴⁺+Cu⁺. Moreover, using different copper precursors significantly changed the redox ability of the adsorbent surface. Changing the copper precursor also had a significant effect on the locations of Cu and Ce ions, and using Cu(Ac)₂ as a metal precursor facilitated the migration of Cu⁺ (53.6%) and cerium species (35.9%) to the supercage. In situ infrared characterization showed that the oligomerization of thiophene on CuCeY_A was significantly restricted due to the lowest B acid content (11.85%) in the CuCeY_A.