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

Abstract

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.