Lean NOx trap catalysts with high low-temperature activity and hydrothermal stability
| Autor: | Pyung Soon Kim, Chang H. Kim, Beom-Sik Kim, Hyunjoo Lee, Junemin Bae, Hojin Jeong |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Process Chemistry and Technology
chemistry.chemical_element Sintering 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Dispersion (geology) 01 natural sciences Catalysis Hydrothermal circulation 0104 chemical sciences chemistry Physisorption Chemical engineering Chemisorption 0210 nano-technology Platinum NOx General Environmental Science |
| Zdroj: | Applied Catalysis B: Environmental. 270:118871 |
| ISSN: | 0926-3373 |
| DOI: | 10.1016/j.apcatb.2020.118871 |
| Popis: | A combination of the Pt-BaO/CeO2 and Cu/CeO2 (PBC + CC) catalyst offers high NOx storage and reduction (NSR) performance at low temperatures; however, the PBC + CC catalyst is prone to deactivation upon hydrothermal aging. In this study, we used a reduced γ-Al2O3 support with unsaturated penta-coordinated Al3+ sites, which can anchor catalytic materials (Pt, Cu, BaO, and CeO2). The physical mixture of Pt-BaO-CeO2 and Cu-CeO2 deposited on the reduced Al2O3 (PBCrA + CCrA) was prepared and tested for the NOx removal. The PBCrA + CCrA catalyst showed little degradation after hydrothermal aging at 750 °C. XRD, HR-TEM, CO chemisorption, N2O chemisorption, and N2 physisorption results showed that catalytically active phases were barely changed even after the hydrothermal aging, particularly preventing ceria sintering. CO-TPR and XPS results demonstrated that the PBCrA + CCrA catalyst has a superior reducibility of lattice oxygen on CeO2, leading to excellent low-temperature activity. |
| Databáze: | OpenAIRE |
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