Hydrogen production by high temperature water gas shift reaction over highly active and stable chromium free Fe–Al–Ni catalysts

Abstract

High temperature water gas shift reaction is carried out over nanocrystalline chromium free Fe2O3–Al2O3–NiO catalysts with and without alkaline earth promoters. Mesoporous catalysts are prepared by coprecipitation method. The prepared catalysts are characterized using N2 adsorption (BET), temperature-programmed reduction (TPR) and desorption (TPD), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results indicate that alkaline earth promoters improve the catalytic activity and suppress the progress of methanation reaction, which is related to the increment of amount in weakly basic sites through promoter addition. Furthermore, it is found that the Fe2O3–Al2O3–NiO catalyst promoted by Ba exhibits the highest catalytic activity and the lowest methanation among the prepared catalysts and the commercial chromium containing one. In addition, the effect of Ba content on the CO conversion is investigated and the results indicate that the catalyst with 3 wt.% Ba possesses high activity and stability without any decrease in CO conversion during 50 h time on stream.