HYDROCARBON SYNTHESIS OVER FE/ZEOLITE HYBRID CATALYSTS

Zeolite-based FTS catalysts are known to minimize the formation of hydrocarbons beyond the gasoline range, shifting the product distribution towards iso-paraffins, olefins and aromatics through the transformation of the primary FTS products on their acid sites. Results in literature demonstrate that the zeolite topology and the Si/Al ratio (15-140) exert a strong effect on the activity, selectivity and stability of the catalyst. Those effects have been studied for both Co- and Fe-based catalyst and various zeolites (ZSM-5, MCM-22, ITQ-2, etc.), but several aspects such as the presence of aromatics as a function of acidity and the influence of zeolite mesoporosity remain unclear. In this work Fe/ZSM-5 hybrid catalysts have been prepared, characterized and evaluated in the Fischer-Tropsch synthesis of liquid hydrocarbons. The influence of zeolite composition (Si/Al ratio = 15-240) and presence of mesoporosity have been investigated.