In situ hydrothermal synthesis of cerium-incorporated X zeolites and their performance in thiophene adsorption

A series of cerium-incorporated X zeolites (Ce(IV)-X) with different Ce/Si molar ratios were prepared by in situ hydrothermal synthesis and used as adsorbents to remove thiophene from a model fuel. The synthesized Ce(IV)-X zeolites were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), diffuse reflectance ultraviolet spectroscopy (UV-vis DRS), plasma atomic emission spectrometry (ICP-AES), N₂ adsorption, and NH₃ temperature programmed desorption (NH₃-TPD). Results reveal that the synthesized Ce(IV)-X zeolites exhibit typical structure of X zeolites and cerium (IV) ions are well dispersed in the framework of X zeolites. The acidity of Ce(IV)-X is enhanced by incorporating cerium, especially at high cerium content. The synthesised Ce(IV)-X zeolites exhibit better capability for the adsorption of thiophene from the model fuel than X zeolites; the Ce(IV)-X sample with n(Ce)/n(Si)=0.05 performs best, possessing a saturated adsorption amount of 52.541 9 mg/g. Moreover, the spent Ce(IV)-X after regeneration still has a perfect adsorption ability towards thiophene; the regenerated Ce(IV)-X sample with n(Ce)/n(Si)=0.05 has a saturated adsorption amount of 47.512 1 mg/g, i.e. 90.43％ of that for the fresh adsorbent.