Properties and Potential Applications of Manganese‐doped Ceria Gained by Mechanochemical Synthesis

Manganese doped nanosized ceria samples were prepared by mechanochemical synthesis. Characterization was done using X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), X-ray photoelectron spectroscopy (XPS) and others. Different conditions of synthesis were tried. Beside cerium carbonate, cerium chloride and amorphous phase remain in the product. Cerium carbonate decomposes around 250 °C, while the decomposition process centered at 330 °C was attributed to cerium chloride decomposition. Along with ceria, birnessite occurs in doped samples after thermal treatment and washing. Ceria lattice constant is reduced from 5.405 Å for pure sample to 5.401 Å for the 30 % doped sample as a consequence of manganese entrance in the ceria lattice. Ceria bandgap is significantly reduced with doping. Particle size was far greater than crystallite size due to a strong tendency toward agglomeration. All prepared powders proved to be efficient catalysts for toluene oxidation with the 30 % doped sample being the most promising.