Understanding the Role of Rare Earths in Zeolite Y on the Removal of Sulfur from Hydrocarbon Fuels

Adsorptive desulfurization is a promising alternative to hydrodesulfurization for minimizing harmful sulfur emissions from hydrocarbon fuels. Cu in Y zeolite (CuY) has shown effective sulfur adsorption, especially when paired with Ce (CuCeY). This study explores other rare earths (REs), including La, Sm, and Nd, in RE and CuRE Y and mesoporous Y (SAY) zeolites for the adsorption of benzothiophene (BT) and dibenzothiophene (DBT). Metal loadings on the zeolites were quantified by using inductively coupled plasma optic emission spectroscopy (ICP-EOS) and X-ray fluorescence (XRF). Characteristic adsorption modes, such as σ-bonding and π-complexation, were observed by using Fourier-transform infrared spectroscopy (FTIR). X-ray diffraction (XRD) Rietveld refinement determined that RE ions prefer the sodalite cages of Y zeolite, while Cu occupies supercage sites. Ce showed the strongest synergy with Cu compared to the other REs and the highest adsorption capacity. The results of this study provide insight into the role of RE exchanged Y on sulfur adsorption.