Pt–Ru/Ba/Al2O3–Ce0.33Zr0.67O2: An effective catalyst for NOx storage and reduction

• Ce0.33Zr0.67O2 solid solution was formed in Pt–Ru/Ba/Al2O3–Ce0.33Zr0.67O2.
• The addition of Ru improves performances of NOx storage and reduction.
• The addition of Ru decreases reduction temperature of Pt.
• The addition of Ru promotes the oxidation of nitrite to nitrate.

An effective catalyst of NOx storage and reduction (NSR), Pt–Ru/Ba/ACZ (ACZ = Al2O3–Ce0.33Zr0.67O2), has been presented through using ACZ as a support. The catalyst was well characterized by XRD, TEM, N2 physisorption, H2-TPR and XPS. Ce0.33Zr0.67 solid solution was formed in the catalyst. The effects of Ru addition on NSR performances were investigated. In comparison with Pt/Ba/ACZ, the addition of Ru in Pt–Ru/Ba/ACZ drops the reduction temperature of Pt, an obvious promoting effect on NSR was observed above 200 °C. The presence of 5 vol% CO2 in feed gas shows an inhibiting effect on NOx storage and reduction.

Pt–Ru/Ba/Al2O3–Ce0.33Zr0.67O2 shows superior performances in NOx storage and reduction to Pt/Ba/Al2O3–Ce0.33Zr0.67O2. The addition of Ru has resulted in decrement of the reduction temperature of Pt and the transformation temperature of NOx storage route from nitrite to nitrate.Figure optionsDownload high-quality image (169 K)Download as PowerPoint slide