Improved performance of Mn ion substituted Ceria nanospheres for water gas shift reaction: Influence of preparation conditions

The present study reports the development of noble metal free nano-catalysts for low-temperature CO oxidation and Water gas shift reaction. Mn-substituted CeO2 solid solution catalysts were synthesized by co-precipitation, combustion and hydrothermal methods and characterized by various physicochemical techniques. The formation of the solid solution was confirmed by XRD. Raman spectroscopic confirmed the oxygen vacancies. The surface area, pore volume and pore size distribution confirmed by N-2 physisorption analysis, whereas, XPS, UV-vis diffuse reflectance spectroscopy confirmed the oxidation state of the Mn ion. The particle size and morphology (spherical shape) of the material was confirmed using FESEM and HRTEM analysis. The resultant Ce1-xMnxO2-delta catalysts were subjected to CO oxidation and influence of various parameters was examined. Typical results indicated that the co-precipitation favored the best active catalyst.