Optimization of NOx Storage Performance through Modifying Catalyst Composition and Alumina Support

The usage of lean-burn engines is a promising strategy for improving the fuel economy of vehicles and reducing the emission of greenhouse gas CO2. The most complex challenge for leanburn engines is the need to find a solution for the increased levels of NOx emissions. Lean NOx trap (LNT) or NOx storage-reduction (NSR) catalysts provide a very effective method for NOx removal in lean-burn gasoline engine exhaust. In this work, we will be focusing on the optimization of NOx storage performance through modifying the catalyst composition in Ba-based NOx storage catalytic materials. We intentionally prepared relevant Al2O3-supported BaO with modification of NO2 storage component by addition of K2O and MgO to widen the lean NOx storage operation window. Other additives, such as La2O3 and TiO2 were also added to modify support Al2O3 before loading of BaO-based storage component. The NO2 storage and releasing characteristics for these catalytic materials with and without the presence of Pt were investigated using TG-IR. Other methods such as XRD and BET were used to characterize structural and surface properties. The roles of these materials are discussed in light of LNT performance.