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Abstract We report a single atom Rh1/CeO2catalyst prepared by the high temperature (800 °C) atom trapping (AT) method which is stable under both oxidative and reductive conditions. Infrared spectroscopic and electron microscopy characterization revealed the presence of exclusively ionic Rh species. These ionic Rh species are stable even under reducing conditions (CO at 300 °C) due to the strong interaction between Rh and CeO2achieved by the AT method, leading to high and reproducible CO oxidation activity regardless of whether the catalyst is reduced or oxidized. In contrast, ionic Rh species in catalysts synthesized by a conventional impregnation approach (e. g., calcined at 350 °C) can be readily reduced to form Rh nanoclusters/nanoparticles, which are easily oxidized under oxidative conditions, leading to loss of catalytic performance. The single atom Rh1/CeO2catalysts synthesized by the AT method do not exhibit changes during redox cycling hence are promising catalysts for emission control where redox cycling is encountered, and severe oxidation (fuel cut) leads to loss of performance.
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CeO 2 Nanostructures Prepared by Selective Water‐Soluble Sr 3 Al 2 O 6 (SAO)‐CeO 2 Vertically Aligned Nanocomposite
The unique redox properties and high oxygen capacity of nanostructured CeO2demonstrate a wide range of applications, such as electrolytes for solid oxide fuel cells, gas sensors, and catalysis for automotive exhaust gas. Most CeO2nanomaterials are prepared by chemical synthesis or hard templating methods. An effective way to obtain highly textured, small‐radius dimensions with high specific surface area remains challenging. Here, highly textured CeO2nanostructures with various shapes ranging from nanowires to nanoporous thin films are successfully synthesized. Vertically aligned nanocomposites (VANs) of Sr3Al2O6(SAO) and CeO2are synthesized first while varying concentration ratio between them. Once the SAO is dissolved in water, the remaining CeO2forms distinct nanostructures. The thermal stability of the nanostructured CeO2is evaluated byin situheating XRD and thermal annealing tests. This method provides an alternative approach to preparing nanostructured CeO2without toxic chemical solutions or complex micro/nanofabrication techniques. These results present a novel approach to prepare nanostructured CeO2for future sensing and energy device applications.
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- PAR ID:
- 10639994
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Engineering Materials
- Volume:
- 27
- Issue:
- 17
- ISSN:
- 1438-1656
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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