NO reduction by CO over gold catalysts supported on Fe-loaded ceria

Nanosized gold catalysts on Fe-loaded ceria were studied in NO reduction by CO in the presence of H-2 and water. The Fe-modified ceria supports (5, 10 and 20wt% Fe2O3) were synthesized by two different methods: mechanochemical mixing (MM) and impregnation (IM) methods. Gold (3 wt%) was loaded by deposition-precipitation method. The samples was characterized by XRD and H-2-TPR measurements; Mossbauer spectroscopy results of fresh and used catalysts were used for clarifying the role of Fe addition. It was established that the presence of very small gold particles was not of crucial importance. The Fe-modification of ceria was beneficial for NO conversion, however it decreased the selectivity to N-2 by increasing the selectivity to N2O. The 100% selectivity to N-2 at 250 degrees C as well as a high catalytic activity and stability was observed over gold catalyst on ceria support containing 5 wt% Fe2O3 and prepared by IM method. (C) 2015 Elsevier B.V. All rights reserved.