Synthesis and Characterization of HighTemperature Stable Nanocomposite Catalysts

Unusually active and sinter-resistant nanocomposite materials were synthesized by combining the high reactivity of nanosized noble metal particles with the excellent hightemperature stability of hexa-aluminates through a simple one-step microemulsion-templated sol-gel synthesis. The novel nanocomposite catalysts were characterized by TEM, XRD, DTA and BET measurements after calcination at temperatures between 600C and 1300C, and were tested in the high-temperature partial oxidation of methane. The materials showed very high activity and selectivity along with excellent stability with respect to surface area, noble metal dispersion and catalytic activity over prolonged operation at reaction temperatures between 900 and 1100C. To our knowledge, this is the first time that metal nanoparticles have been stabilized to such extreme high temperature conditions. We see these novel materials therefore not only as very promising candidates for hightemperature catalytic applications, but generally view this as a possible route to expand the parameter range for nanoparticle applications.