Abstract: The influence of lanthanum and cerium cations on the stability of Y zeolite was studied by X-ray diffraction, X-ray photoelectron spectroscopy, solid-state NMR spectroscopy, scanning electron microscopy, and energy dispersion spectroscopy. Although the stability of Y zeolite could be enhanced by the introduction of La or Ce cation, the La showed more remarkable effect than Ce. These results were con-firmed theoretically by density functional calculation. There was a strong interaction between the rare earth species and Y zeolite clusters, which restrained the formation of extra-framework alumina and evidently enhanced the stability of Y zeolite. Furthermore, the interaction between La species and Y zeolite was stronger.

Key words: Y zeolite, lanthanum, cerium, stability, density functional theory, mechanism