Effect of Iron Precursor on the Preparation of Mesoporous Nanocrystalline Chromium Free Fe2O3-Al2O3-NiO Catalyst for High Temperature Water Gas Shift Reaction

Mesoporous nanocrystalline Cr-free Fe-Al-Ni catalysts were synthesized by coprecipitation method and employed in high temperature water gas shift reaction. The effects of iron precursors such as ferric sulfate and ferric nitrate on the structural and catalytic properties of the prepared catalysts were investigated. The catalysts were characterized by powder X-ray diffraction (XRD), N2 adsorption (BET), Temperature programmed reduction (TPR) and transmission electronmicroscopy (TEM) techniques. The TEM analysis showed the crystallite size smaller than 15 nm for the catalyst prepared with nitrate precursor. The catalytic results showed that the prepared catalyst with nitrate precursor exhibited higher catalytic activity than the catalyst prepared with sulfate precursor and the commercial chromium containing one. In addition this catalyst possessed a high surface area of 177.4 m2 g-1 with an average pore size of 4.4 nm with a high stability during 20 h time on stream.

Keywords:

Cr-free catalyst , Fe2O3 , Nanostructure , Iron based catalyst , Water-gas shift , ferric nitrate