A study of surface and inner layer compositions of Mg-Fe-Al-O mixed spinel sulfur-transfer catalyst using Auger electron spectroscopy

The compositions of the surface and the bulk of Mg-Fe-Al-O mixed spinel catalyst have been studied using the AES technique. The behaviour of surface segregation of the magnesium and oxygen atoms and the enrichment of iron and aluminum atoms in the bulk have been identified. It has been found that both the capacity of sulfur-capturing and the ability of sulfur species reduction for the iron-containing catalyst are much higher than that of the MgAl₂O₄ catalyst, which suggests that the iron element has an important role in the cycle between SO₂ oxidative adsorption and sulfate reductive desorption.