Fe-modified HZSM-5 catalysts for ethanol conversion into light olefins

A series of Fe/HZSM-5 catalysts with different iron loadings were prepared by impregnation method. Characterization was performed by N2 adsorption-desorption, X-ray diffraction (XRD), NH3 temperature-programmed desorption (NH3-TPD), temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO) and thermogravimetry (TG) analysis. Iron content in the synthesized samples varied from 1.1 wt% to 20 wt%. The obtained samples have been used for ethanol conversion into light olefins. It was found that the amount of strong acidity at 300-550 °C on Fe-modified samples was decreased, going with another new acid site appearance at 550-600 °C and that Fe/HZSM-5 catalysts were highly selective towards light olefins, especially the 9FZ sample. In addition, Fe-modified catalysts suppressed the conversion of ethanol to aromatics and paraffins and enhanced their anti-carbon deposit ability.