Novel oxygen storage components for advanced catalysts for emission control in natural gas fueled vehicles

Advanced catalysts based on a novel oxygen storage component (OSC) were developed for emission control in natural gas fueled vehicles. The catalysts contain a manganese oxide (MnOx) as the OSC supported on an inert LaAlO3 perovskite and a noble metal component (Pd) supported on a separate high surface area refractory material, for example lanthana stabilized Al2O3. The MnOx has higher oxygen storage capacity, and faster oxygen absorption and oxide reduction rates than the present commercial ceria-stabilized alumina support materials. Temperature programmed techniques and dynamic cycled experiments were used to measure oxygen storage capacity, activity for NO reduction and CO and CH4 oxidation rates. Durability tests on a physical mixture of Pd-Mn/LaAlO3 and Pt/Al2O3(La) demonstrated that a temperature excursion to 950 degrees C for 30 min did not cause significant loss in catalyst activity for either NO reduction or CO or CH4 oxidation. We have also shown that the MnOx can be added to conventional three-way catalysts (TWC) to enhance their performance for NOx reduction and CO or hydrocarbon oxidation.