The synthesis of ceria-based mixed oxides via an oxalate-gel method and the testing of their catalytic activity in the carboxylation of methanol with CO2 are described. The evaluation of their activity is performed in liquid phase. With ceria, the influence of pressure, reaction temperature, and composition of the reactants in the gas and liquid phase are investigated. Moreover, the thermodynamics of the reaction and the structural properties of the catalysts, characterized by X-ray diffraction, FTIR- and UV/VIS spectroscopy, and physisorption, are discussed.