Preparation and characterization of promoted Fe–Mn/ZSM-5 nano catalysts for CO hydrogenation

Abstract

In the present work, a series of iron based catalysts supported on ZSM-5 were prepared using incipient wetness method and tested for C2–C4 light olefins production from syngas (CO + H2). The effects of Fe and Mn loading, calcination conditions, different promoters, wt.% K as an optimal promoter and operational conditions on the catalytic performance of the optimal catalyst were investigated. It was found that the catalyst containing 8% Fe/2.4%Mn/ZSM-5 promoted with 2 wt.%K had the best catalytic performance for light olefins production. The best operational conditions were H2/CO = 2/1 M feed ratio, T = 270 °C, gas hourly space velocity (GHSV) = 2600 h−1 and 1 bar pressure. Catalysts and precursors were characterized by X-ray diffraction (XRD), transmission electron microcopy (TEM), thermal gravimetric analysis (TGA), temperature program reduction (TPR), Scanning electron microcopy (SEM), differential scanning calorimetry (DSC) and N2 adsorption–desorption measurements. The TPR spectrum for 8% Fe/2.4%Mn/ZSM-5 showed lower reduction temperatures respect to similar Fe–Mn catalysts.