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

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 CeO2 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 CeO2 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 NH3-TPD and H2-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 CeO2, where the strong interaction of Ru-Ce is able to gain a high synergy for NO and CO conversion.

Acid-Base Surface-Driven NO-CO Conversion over Copper-Manganese-Based Metal Oxides.

Recently, tuning catalytic material has gained huge importance for enhancing the catalytic performance of reactions. The present work describes the influence of aluminum in copper-manganese composite oxide with respect to the NO-CO redox reaction. The Al3+ fabricated composite oxide showed the highest conversion in a lower temperature window. The nanocomposite metal oxide of Cu-Mn formed as a porous structure with aluminum and helped in establishing a more surface acidic/basic character on the catalyst. These acidic/basic sites are crucial in activating the NO and CO chemisorption for significant redox conversion.

Synergistic effect of modified Pd-based cobalt chromite and manganese oxide system towards NO-CO redox detoxification reaction.

Surface architecting of the catalyst is a hopeful method to expand the surface property of the impetus material for upgrading their response towards the chemical reaction. In the present study, designing of the catalyst was carried out using specific transition metals to boost the simultaneous NO-CO conversion reaction catalytically. These metal oxide systems have been prepared using the combustion and wet impregnation method. Prepared oxides were characterized using XRD, BET, XPS, SEM, and TEM. Further, the surface phenomenon of the catalyst was monitored through H2-TPR, O2-TPO, NO-TPD, and CO-TPD studies. The highly remarkable activity was perceived by Pd-based modified manganese oxide-cobalt chromite system as compared with simple Pd-based manganese oxide and Pd-based cobalt chromite. The catalyst showed the highest activity for NO-CO redox reaction with T100 at 170 °C. Also, good stability was observed with a runtime of 7 h.