A highly active and stable chromium free iron based catalyst for H2 purification in high temperature water gas shift reaction

•Nanocrystalline Fe–Al–Ni Cr-free catalysts were evaluated in HTS reaction.•Preparation parameters affected the structural properties of the Fe–Al–Ni catalyst.•Fe–Al–Ni catalyst (Fe/Al = 10, Fe/Ni = 5) showed the highest activity.•Fe–Al–Ni catalyst presented higher activity compared to commercial Fe–Cr catalyst.•Effect of calcination temperature was studied on Fe–Al–Ni catalyst.

In this work mesoporous nanocrystalline chromium free Fe–Al–Ni catalysts with various Fe/Al and Fe/Ni ratios were prepared by coprecipitation method for high temperature water gas shift reaction. The prepared catalysts were characterized using X-ray diffraction (XRD), N2 adsorption (BET), temperature-programmed reduction (TPR) and transmission electron microscopy (TEM) techniques. The catalytic results revealed that the catalyst with Fe/Al = 10 and Fe/Ni = 5 weight ratios exhibited the highest catalytic activity among the prepared catalysts and the commercial chromium containing one. This catalyst possessed a high surface area of 177.4 m2 g−1 with an average pore size of 4.3 nm with a high stability during 20 h time on stream. Furthermore, the effect of calcination temperature, GHSV and steam/gas ratio on the structural properties and catalytic performance of the catalyst with the highest activity was investigated.

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