Storage capacity and oxygen mobility in mixed oxides from transition metals promoted by cerium

• Published in: Applied surface science 2016-10, Vol.383, p.42-48
• Main Authors: Perdomo, Camilo, Pérez, Alejandro, Molina, Rafael, Moreno, Sonia
• Format: Article
• Language: English
• Subjects: Catalytic activity; Cooperative effect; Electron paramagnetic resonance; Isotopic exchange; Mixed oxides; OSC; Oxides; Oxygen; Oxygen vacancies; Storage capacity; Titration; Transition metals
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.04.145

[Display omitted] •Ce addition to the catalysts improves the availability of oxygen in the materials.•Mixed oxide with Co and Cu exhibits the best oxygen transport properties.•Co presence improves O2 mobility in the catalysts.•The presence of Cu in the solids improves redox properties. The oxygen mobility and storage capacity of Ce-Co/Cu-MgAl or Ce–MgAl mixed oxides, obtained by hydrotalcite precursors, were evaluated using Toluene-temperature-programmed-reaction, 18O2 isotopic exchange and O2-H2 titration. The presence of oxygen vacancies-related species was evaluated by means of Electron Paramagnetic Resonance. A correlation was found between the studied properties and the catalytic activity of the oxides in total oxidation processes. It was evidenced that catalytic activity depends on two related processes: the facility with which the solid can be reduced and its ability to regenerate itself in the presence of molecular oxygen in the gas phase. These processes are enhanced by Cu-Co cooperative effect in the mixed oxides. Additionally, the incorporation of Ce in the Co-Cu catalysts improved their oxygen transport properties.