Authors:H. Nasser, Á. Rédey, Tatiana Yuzhakova, and J. Kovács
In order to explore the influence of CeO2 on the structure and surface characteristics of molybdena, an investigation was undertaken by using N2 adsorption (BET method), thermal analysis and in-situ diffuse reflectance infrared (DRIFT) techniques. In this work, the
Mo/CeO2 and Ce-Mo/Al2O3 samples were prepared by impregnation and co-precipitation methods with high Mo loadings. Combining the results one may notice
that the presence of ceria led to the increase of polymerized surface Mo species so as to forming Mo-O-Ce linkages besides
the formation of coupled O=Mo=O bonds indicative of polymeric MoO3.
From thermal analysis, it can be inferred that Mo/Al2O3 is the thermally most stable material in the temperature range used in the experiment (up to 900°C), whereas Ce-Mo/Al2O3 and Mo/CeO2 samples undergo morphological modifications above 700°C resulting in lattice defects, which motivate the mobility of Mo and
Ce ions and thus enhance the possibility of interaction between them. Additionally, their activity towards CO adsorption needs
reduced ceria and molybdena containing coordinatively unsaturated sites (CUS), oxygen vacancies and hydroxyl groups to form
various carbonate species.