The preparation and characterization of highly dispersed PdO over alumina for low-temperature combustion of methane

PdO/Al2O3 catalysts prepared by glow discharge plasma treatment followed by thermal calcination show a much higher dispersion and a better catalytic activity for methane combustion at relatively low temperatures, The dispersion of palladium active species by such plasma prepared catalysts is 29.7%, 5.4 times higher than that of conventional catalysts. XPS analysis indicates that a surface enrichment of Pd active species (PdO) has been achieved after plasma treatment. The surface atomic composition of PdO of plasma prepared catalysts reaches 10.5%. XRD characterization also confirms a well-crystallized PdO phase present on the plasma prepared catalyst. The light-off temperature of the plasma prepared catalyst is 370degreesC, 50degreesC lower than that obtained from the conventional catalyst.