Effect of Co and Rh promoter on NOx storage and reduction over Pt/BaO/Al2O3 catalyst

Effect of cobalt and rhodium promoter on NOx storage and reduction (NSR) kinetics was investigated over Pt/BaO/Al2O3. Kinetics of 2% cobalt loading over Pt/BaO/Al2O3 demonstrated highest NOx uptake during lean cycle, while reduction efficiency during rich cycle appeared most poor. In contrast to this, rhodium showed suppressing effect of NOx uptake during lean cycle and demonstrated an enhanced effect for the higher efficiency of NOx reduction during rich cycle. DRIFT study for NOx uptake and regeneration confirmed formation of surface BaNOx from the band at 1300 cm−1 and formation of bulk BaNOx from the band at 1330 cm−1.