Purification of Gasoline Exhaust Gases Using Bimetallic Pd-Rh/δ-Al2O3 Catalysts
In the present work, a series of palladium- and rhodium-containing samples supported on delta-alumina was prepared. Monometallic samples containing corresponding metal loading serve as the references. Catalytic performance of the catalyst was studied in three-way catalysis under both the stoichiometric and reductive conditions. Thermal stability was examined using a prompt thermal aging procedure. The samples were characterized by means of luminescence and UV-vis spectroscopies, since due to low metal loading the most of other characterization techniques was not applicable. All the samples were found to undergo deactivation during the aging. At the same time, for bimetallic Pd-Rh systems an effect of reactivation was observed at 800 °C. Then, being subjected to the treatment at 1000 °C, these samples showed a rapid agglomeration of the active particles.