Redox behaviors and structural characteristics of Mn0.1Ce0.9Ox and Mn0.1Ce0.6Zr0.3Ox

Abstract Mn 0.1 Ce 0.9 O x and Mn 0.1 Ce 0.6 Zr 0.3 O x samples synthesized by sol-gel method were tested for redox properties through the dynamic oxygen storage measurement and characterized using X-ray diffraction, BET, electron paramagnetic resonance, and X-ray photoelectron spectroscopy. The results showed that redox performances of ceria-based materials could be enhanced by synergetic effects between Mn-O and Ce-O. Fresh and aged samples were characterized with the fluorite-type cubic structure similar to CeO 2 , and furthermore, the thermal stability of Mn 0.1 Ce 0.9 O x materials was improved by the introduction of some Zr atoms. From XPS, it could be concluded that Mn 2+ /Mn 3+ redox couples existed on the surface of Mn 0.1 Ce 0.9 O x and Mn 0.1 Ce 0.6 Zr 0.3 O x samples. Electron paramagnetic resonance researches revealed that there were three types of Mn 2+ species: isolated Mn 2+ substituting for Ce 4+ ions in the lattice with a cubic symmetry, ones in defect with a noncubic symmetry, and at the surface of samples.