Raman scattering of MnO x CeO x composite catalysts: structural aspects and laser‐heating effects

Composite MnO x CeO x catalysts (Mn at : Ce at = 1) synthesized via the redox and coprecipitation routes were comparatively characterized by micro‐Raman spectroscopy using a laser irradiation power ranging between 0.6 and 4.2 mW. A quasi‐molecular dispersion of the oxide species determines a major and irreversible structural rearrangement of the redox MnO x CeO x system because of severe heating effects for laser power in excess of 0.6 mW. The X‐ray diffraction data of samples calcined in the range of 6731273 K confirm that the micro‐Raman characterization of the composite MnO x CeO x systems requires an adequate minimization of the irradiation power to prevent the strong sintering and restructuring phenomena due to laser‐heating effects. Copyright © 2011 John Wiley & Sons, Ltd.