Thermally stable environmental catalyst: Oxidation of methane over calcined palladium loaded on silica monolayer

Enhancement of thermal stability of the Pd loaded on alumina for the complete oxidation of hydrocarbons was studied by preparing the surface of a support consisting of a partially covered silica monolayer and remaining alumina by a chemical vapor deposition of silicon alkoxide. The thermal stability of the Pd-loaded silica-deposited alumina was tested after the calcination at 1493 K. The silica monolayer not only maintained the high surface area, but also suppressed the sintering of palladium. After the calcination, the catalytic activity of Pd/10 wt% SiO2/Al2O3 was double that on Pd/Al2O3, although it decreased to 1/10 of the initial activity. The support and loaded palladium were characterized by BET, XRD, TEM and TPR measurements.