NOx storage and reduction by H-2 over highly dispersed Pt on Co1Mg2Al1Ox-LDO for stationary applications: A transient kinetic study

The performance of a highly dispersed Pt/Co1Mg2Al1Ox-LDO catalyst towards NOx-storage and reduction by H-2 for NOx control in stationary applications was investigated under forced feed composition cycling (swing-reactor system). The influence of 7 vol% CO2 and 5 vol% H2O in the NO-containing and H-2-containing feeds on the dynamic evolution of adsorbed NOx-s and their reduction performance (conversion and N-2-selectvity) were determined in the 200-400 degrees C range. The effects of catalyst pretreatment with 20 or 50 ppm SO2/He gas mixture on its NOx-s storage and reduction by hydrogen dynamics were also investigated. Reduction of NOx-s formed on the support involves a hydrogen spillover effect from Pt to the metal-support interface and support NOx-s sites. A very stable NSR performance was obtained at 350 degrees C for 2 h of successive NOx-adsorption (3 min)/reduction by H-2 (1 min) steps. The nature of active and inactive NOx-s in H-2 was probed by in-situ DRIFTS.

Automated summary

The performance of a highly dispersed Pt/Co1Mg2Al1Ox-LDO catalyst towards NOx adsorption and reduction by H2 was investigated. The influence of CO2 and H2O in the feeds, and the effects of catalyst pretreatment with SO2/He gas mixture on NOx dynamics were determined. The nature of active and inactive NOx species in H2 was probed by in-situ DRIFTS.