CO and Hydrocarbon Oxidation on Pd/Ceria-Zirconia/Alumina Three-way Catalysts
CO, C2H2, and C3H6 were observed to be self-inhibiting. For the same concentrations of carbon (ppm C1 basis) in the feed mixture, C2H2 oxidation occurs at higher temperatures than C3H6 oxidation. Mutual inhibition effects were also examined for binary and ternary mixtures of CO, C2H2, and C3H6; C2H2 was observed to strongly inhibit CO and C3H6 oxidation in mixtures. For singular and mixture oxidation experiments, LO temperatures were lower using the Pd/Ceria-Zirconia catalyst compared to using Pd/Al2O3, demonstrating the promotional effects of using
ceria. Steady-state kinetics measurements during individual species oxidation were conducted to
find reaction orders and activation energies of oxidation. Ongoing work involves the use of a
mechanistic-based kinetic model incorporated into a low-dimensional monolith reactor model.
The reactor model comprises coupled, transverse-averaged species and energy balances and
aforementioned kinetics. The reactor model is used to verify and predict experimental LO
behavior and trends during individual and co-oxidation using catalysts and feed mixtures of