Improved performance of Mn ion substituted Ceria nanospheres for low temperature CO oxidation and Water gas shift reaction: Influence of Calcination Temperature and Synthetic route

The catalytic activity described herein is aimed to portray various features associated with performance of manganese doped mesoporous ceria matrix. Ce0.8Mn0.2O2-is synthesized by facile co-precipitation, hydrothermal, combustion methods and calcined at 4000C, 6000C, and 8000C. The activity tests demonstrate catalytic performance of Ce0.8 Mn0.2O2 4000C is the best. The catalyst is characterized by physico-chemical techniques. XRD with Rietveld refinement points out decrease of crystallite size of manganese doped ceria. The absence of peak at 4000C corresponding to dopant predicts generation of Ce-Mn-Ox solid solution. BET-surface area measurement is employed to evaluate the structural properties like pore size, pore volume, surface area of the synthesized catalysts. SEM and TEM analysis determine spherical shape, state of aggregation, hexagonal surface morphology. UV-vis, Raman spectroscopic study are utilized to find oxygen vacancies. The present reporting minutely illustrates the outperforming aptitude CM-4000C among nine competitive catalysts. Their catalytic behavior towards CO oxidation is executed with 0.8 vol% CO with GHSV of 21,000 h-1 as a model reaction with molecular oxygen as oxidant