A highly active and stable chromium free iron based catalyst for H_2 purification in high temperature water gas shift reaction

摘要

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), N_2 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 m~2 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.