C₂-C₄ light olefins from bioethanol catalyzed by Ce-modified nanocrystalline HZSM-5 zeolite catalysts

Conversion of bioethanol into bulk chemicals besides ethylene is a promising process in which the stability of catalyst and the selectivity of products are important. In this study, a series of Ce-modified nanocrystalline HZSM-5 catalysts were prepared and their catalytic performance in the conversion of bioethanol into C₂-C₄ light olefins was investigated in a fixed-bed reactor at 400°C under atmospheric pressure. The results show that the stability of catalyst and the distribution of products depend strongly on the content of cerium and the calcination temperature; both cerium content and calcination temperature affect not only the acid properties of the tested catalyst samples but also the composition of cerium species (Ce³⁺/Ce⁴⁺) as revealed by XPS. Among the tested catalyst samples, the catalyst with 5wt% cerium loading and 520°C calcination temperature exhibits the best stability and selectivity to C₃-C₄ light olefins.