(205g) Highly Stable Pt-Bha Nanocomposite Catalysts for Low-Temperature CO Oxidation

Oxide-supported metal nanoparticles have attracted much attention in catalysis. In particular, strong size-effects in CO-oxidation over nano-sized gold catalysts have been extensively studied because of this reactions simplicity, fundamental character, and its importance in energy technology. However, most nanocatalysts to-date are plagued by insufficient stability at reactive conditions. To overcome this limitation, we are developing nanocomposites which combine the high reactivity of nano-sized noble metal particles with the stability of hexa-aluminates.

Here, we present results from an investigation in which Pt-BHA nanocomposites were synthesized and characterized (SEM, TEM, XRD, BET, and chemisorption), and tested in low-temperature CO oxidation. Kinetic studies via in-situ FTIR over a temperature range of T = 200 - 300 K show an exceptionally low activation energy of ~ 9 kJ/mol, about 3-times lower than for conventional Pt catalysts. CO-TPD studies confirm a strong size-effect for CO desorption energies in the range between 2 ? 10 nm.