Comparison between the NOxNOx release–reduction reaction for Pt/Ba/Al2O3Pt/Ba/Al2O3 and Pt/K/Al2O3Pt/K/Al2O3 on a millisecond time scale

We compared the NOxNOx regeneration process for the storage and reduction reaction of NOxNOx using both Pt/Ba/Al2O3Pt/Ba/Al2O3 and Pt/K/Al2O3Pt/K/Al2O3 on a millisecond time range. The NOxNOx storage process was simulated using pulses of gaseous O2O2 and NO, and the reduction was simulated using pulses of H2H2 gas. When pulses of H2H2 were supplied, the time profiles of N2N2 and NH3NH3 products were measured using a TAP-type reactor with a time-of-flight mass spectrometer. The time profiles of the products during the reduction process depended on the temperature, the amounts of gases and the components of the samples. From an analysis of the NOxNOx reduction reaction using a simple two-step representation of the process, it was found that the rate of reduction of NOxNOx using Pt/K/Al2O3Pt/K/Al2O3 would be larger than reduction using Pt/Ba/Al2O3Pt/Ba/Al2O3. Further analysis using different precious metals will help us to extend our understanding of the NSR reaction mechanism.