Factors controlling catalytic CO oxidation activity on Pd/CeO2-ZrO2-Al2O3 cryogels
| Autor: | Toshihiko Osaki |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Diffusion barrier chemistry.chemical_element Sintering 02 engineering and technology 010402 general chemistry 01 natural sciences Catalysis law.invention Metal Magazine law General Materials Science Mechanical Engineering 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Grain growth chemistry Chemical engineering Mechanics of Materials visual_art visual_art.visual_art_medium 0210 nano-technology Palladium Solid solution |
| Zdroj: | Materials Research Bulletin. 118:110498 |
| ISSN: | 0025-5408 |
| DOI: | 10.1016/j.materresbull.2019.110498 |
| Popis: | Porous and homogeneous 5 wt.% Pd/CeO2-ZrO2-Al2O3 cryogels (Ce/Zr = 1 and Ce/Al = 0–1/2) were synthesized by one-pot sol-gel processing and subsequent freeze drying, and catalysis of CO oxidation was investigated after heating at high temperatures. It was revealed that palladium dispersion and oxygen storage capacity (OSC) were the essential factors to control the CO oxidation activity. It was also revealed that optimized Ce/Al ratio was 1/4 to obtain the highest activity. When the ratio was smaller than the value, stabilization of palladium by ceria was retarded and sufficient OSC was not obtained owing to insufficiency of ceria. Whereas when the ratio was larger than the value, performance of alumina as a diffusion barrier for retarding coagulation and grain growth of the solid solution deteriorated owing to its insufficiency. As a result, encapsulation of palladium into the solid solution and/or sintering of the metal proceeded, which consequently lowered palladium dispersion and OSC. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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