Lower methane combustion temperature on palladium nanoparticles anchored on TiOx subnano-islets in stellate mesoporous silica nanospheres
Palladium oxide nanoparticles of 9 nm stabilized on TiOx subnano-islets (SNI) in monodispersed mesoporous silica nanospheres (MSN) having a stellate morphology are found very active for methane combustion. The characterization at various steps of the catalysts elaboration was performed using a panel of techniques including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–visble reflectance spectroscopy. The catalytic performances were measured from methane combustion light-off experiments showing a remarkably low temperature light-off (T10% ~ 200°C) of these particles in comparison PdO nanophase on 2D TiOx anchors (T10% ~ 280°C) or those obtained without TiOx anchors (T10% ~ 350°C). The surprising performance of these new catalysts is attributed to a combination of parameters along with the stellate pore morphology likely favorable for high conversion and diffusion-controlled regime.