Detection of adsorbed O2− species on CeO2 solid impregnated with Ag2+ ions during its thermal treatment under a H2 atmosphere, an EPR study
10% Ag/CeO2 solid was prepared by the impregnation method. When the solid is calcined at 400 °C, three types of Ag2+ species are formed. One of them is more thermally stable compared to the others. The adsorption on the solid of O2 or H2 molecules gives an adsorbed O2− species on the surface, detected by electron paramagnetic resonance (EPR). The mobility of oxygen in CeO2 and the nature of cations loaded on this support can be the origin of the adsorbed O2− species particularly when the solid is treated under H2 molecules.