Effect of Ion-exchange Sequence of Copper and Cerium on the Performance of Y Zeolite for the Adsorption Removal of Thiophene from Benzene

Abstract

Purposes The bimetallic modified Y zeolite is of great importance for the deep removal of thiophene in coking benzene. The influence of metal ion-exchange sequence on the desulfurization performance of zeolite is crucial. Methods A series of bimetallic modified sorbents were prepared by ion-exchange with Cu and Ce. The desulfurization performance of sorbents in thiophene-benzene solutions was evaluated by static adsorption experiments. The physical and chemical properties of sorbents were analyzed by XRD, Py-FTIR, XPS, H2-TPR, and N2 adsorption and desorption techniques. Findings The results show that metal ion-exchange sequence affects the relative crystallinity, ion-exchange degree, metal content, and L acid amount of sorbent. The correlations between the physical, chemical properties and the desulfurization performance of sorbent indicate that the higher the ion-exchange degree, the higher the desulfurization efficiency of sorbent. Meanwhile, the more Cu＋ and Ce4＋ in the sorbent, the more L acid sites formed and the higher its desulfurization efficiency. When Y zeolite is exchanged by Ce first and then Cu, the metal Ce affects the location of Cu and improves reduction performance of Cu. The desulfurization efficiency order of sorbents is CuCeY>CeCuY>Cu-CeY. The desulfurization efficiency of CuCeY is the highest, reaching 97.3%, and its relative crystallinity is the highest and ion-exchange degree is the largest. This work serves as a guide for the preparation of high efficiency desulfurization sorbents.

Keywords

• cu and ce modified zeolite
• ion-exchange sequence
• thiophene
• adsorption
• desulfurization