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 5 wt% cerium loading and 520 °C calcination temperature exhibits the best stability and selectivity to C3–C4 light olefins.

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► Ce modified nanocrystalline HZSM-5 was used to convert bioethanol into C2-C4 light olefins.
► Ce modification leads to the increase in the ratio of Brőnsted acid sites to Lewis acid sites.
► Both Ce3+ and Ce4+ species present over the surface of catalyst samples after Ce modification.
► The ratio of Ce3+ to Ce4+ can be adjusted by Ce content and calcination temperature.
► Ce modification improves the stability and product distribution.