Low Temperature NO and CO Conversion with a Mechanistic Approach on Ru-Composed Cerium Oxide

Abstract

Catalytic reduction of NO with CO at a lower temperature is an extremely challenging task, thus requiring conceivable surfaces to overcome such issues. Ru-substituted CeO 2 catalysts prepared via the solution combustion method were employed in CO oxidation and NO−CO conversion studies. The characterization for material formation and surface structure was carried out through XRD, SEM, TEM, and BET surface area. The catalytic study revealed the promising behavior of 5% Ru in CeO 2 for the 100% conversion of NO−CO at 150 °C, proving it to be an excellent exhaust material. These observed results are also supported by temperature-programmed studies, i.e. TPD of NO and CO in addition to NH 3 -TPD and H 2 -TPR for their convincible surface interaction that is inclined toward a significant change in the conversion path. Additionally, the proposed mechanism, based on the experimental evidence, sheds light on the NO−CO redox reaction, directing the reaction pathway toward the Langmuir− Hinshelwood and Mars-Van Krevelen-type route. Moreover, the exceptional performance can be attributed to the strategic incorporation of Ru in CeO 2 , where the strong interaction of Ru−Ce is able to gain a high synergy for NO and CO conversion.