Catalytic combustion of methane over mesoporous silica supported palladium

Abstract

Pd nanoparticles with controlled size have been prepared by nanocasting of a mesoporous silica SBA-15. Two methods of impregnation were tested: incipient wetness impregnation and ion exchange. Pd was ion-exchanged with the silanol groups on non-calcined silica, prepared by solvent extraction of the template. The structural and porosity properties of these materials were studied by XRD, N 2 sorption and TEM imaging. The nature of palladium species in these catalysts were investigated by UV–vis, TEM and high angle XRD. Whatever the method of impregnation, the particles of palladium are very small and well dispersed on the surface of support. The solids were tested in the catalytic combustion of methane and in the selective catalytic reduction of NO x with methane. The activity of both catalysts for this last reaction is very low. For methane catalytic combustion, these Pd/mesoporous materials demonstrate higher conversions and the Pd-SBA-15 sample prepared by ion exchange showed a light of temperature (T50) 75 °C lower than the one exhibited by the sample prepared by incipient wetness impregnation.