Enhanced Adsorption Desulfurization Performance over CuCeY Zeolites Prepared by Low‐Temperature Calcination under H₂ Atmosphere

Abstract

In order to optimize the location and valence state of metal ions in the Y‐type zeolite, the bimetallic (cerium and copper) modified NaY (CuCeY) zeolites with different Cu/Ce ratios were prepared by calcination at 180 °C under H2 atmosphere. Their adsorptive capacity and selectivity for thiophene were preliminarily explored. Furthermore, the CuCeY zeolites were characterized by various techniques for explaining their adsorption behaviors. The obtained results show that the breakthrough adsorption sulfur capacity (Q) of CuCeY zeolites from model oil contains thiophene (TMO) shows a volcanic tendency with the increase of Cu ion contents in zeolites. This is because more metal ions, especially Cu+ ions, are distributed to the supercages of Y zeolites. When 1‐hexene coexists with thiophene in model oil (TOMO), the Q of CuCeY zeolites increase firstly and then remain almost unchanged as Cu ion contents in zeolites increases. It is related to competitive adsorption, alkylation and oligomerization of thiophene and 1‐hexene. When benzene coexists with thiophene in model oil (TAMO), the Q of CuCeY zeolites are linear with Cu ion contents in zeolites. This is possible because the competitive adsorption between olefins and sulfur compounds on Cu ions or weak Brönsted(B) acid centers are stronger than that between aromatics and sulfur compounds on the same adsorption sites. It′s worth mentioning that the Q values of CuCeY zeolites are larger than that of bimetallic modified CuCeY zeolites and that of most of monometallic modified Y zeolites reported in the references.