Suppression of Combustion Activity

1 Suppression of Combustion Activity - A remarkable alteration of the typically high combustion activity of Pd occurs in the presence of low concentrations of NO, e.g. a few thousand ppm, typical of exhausts. In a recent study, the methane combustion activity with and without NO in the feed has been compared on a series of Pd catalysts on various supports and with different Pd loadings. It was observed that supports containing Bronsted acidity exhibited a high selectivity towards the selective reduction of NO by methane, and that this selectivity enhancement was accompanied by a drastic decrease of the methane combustion rate. 

NO - In order to explain the drastic effects of the presence of NO in combustion activity, all of the catalysts were characterized by X-ray absorption after reduction in H2 at 300 °C or after exposure to a mixture of CH4/NO/O2 at 500 C, and cooled down in the same mixture.An XANES analysis of the Pd K edge for 

---