In Situ X-Ray Absorption Spectroscopy Study of Copper Ferrite and Copper Aluminate Reduction

Catalysts based on copper ferrite and copper aluminate are highly active in the reaction of CO oxidation. We report a detailed in situ X-ray absorption spectroscopy study of CuFe2O4 and CuAl2O4 reduction in a CO flow in the temperature range from 30 °C to 600 °C. It is shown that the reduction of copper ferrite and copper aluminate in a CO flow leads to the formation of metallic copper. The reduction of copper from Cu2+ to Cu1+ and Cu0 in copper ferrite occurs at lower temperatures (250-300 °C) than in copper aluminate (above 400 °C). The reduction of copper ferrite also leads to the formation of metallic iron as a result of the following stages: CuFe2O4 → Fe3O4 → FeO → Fe.