Influence of TiO₂ on Noble Metal Based Catalysts for Lean NO_x Reduction with CO

The performance of various noble metal based catalysts for the NOxreduction in the CO-rich conditions of simulated post Euro-IV diesel emissions at low temperature was investigated in this paper. Pd loaded catalyst showed higher catalytic activity than Ir or Rh loaded catalysts. Titania, as one of the support material, clearly promoted the deNOxprocess due to the synergy with alumina and Palladium. The TiO2loading was optimized subsequently. As a result, Pd/TiO2/Al2O3catalyst with Pd loading of 2.0 wt.% and TiO2loading of 10 wt.% showed the NOxconversions of 25~46% in the temperature range of 200~250°C.