Preparation and characterization of LaFe1−xMgxO3/Al2O3/FeCrAl: Catalytic properties in methane combustion

A series of the LaFe1−xMgxO3/Al2O3/FeCrAl catalysts (x = 0–1) were prepared. The structure of the catalysts was characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and temperature-programmed reduction (TPR). The catalytic activity of the catalysts for the methane combustion was evaluated. The catalytic stability of the catalysts for 100 h was tested with a fixed bed reactor. The results indicated that in the LaFe1−xMgxO3/Al2O3/FeCrAl catalysts the phase structure were the LaFe1−xMgxO3 perovskite-type oxides, α-Al2O3 and γ-Al2O3. The surface particle shape and size were more different with the variety of the molar ratio of Fe to Mg in the LaFe1−xMgxO3. The Fe component of the LaFe1−xMgxO3/Al2O3/FeCrAl catalysts played an important role to the catalytic activity for the methane combustion and the order of the catalytic activity in terms of x was 0.5 > 0.3 > 0.7 > 0.9 > 0 > 0.1 > 1. In the LaFe1−xMgxO3/Al2O3/FeCrAl catalysts (x = 0.1–0.9) the Fe and Mg components can promote the thermal stability. There were the stronger interaction among the LaFe1−xMgxO3 perovskite-type oxides and the Al2O3 washcoats and the FeCrAl support.