Theoretical study of stability and reaction mechanism of CuO supported on ZrO2 during chemical looping combustion
| Autor: | Fenghua Shen, Yan Long, Minjun Wang, Hao Cheng, Jinxin Dai, Jing Liu |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Reaction mechanism
Chemistry Inorganic chemistry General Physics and Astronomy chemistry.chemical_element Electron donor 02 engineering and technology Surfaces and Interfaces General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Redox Oxygen 0104 chemical sciences Surfaces Coatings and Films chemistry.chemical_compound Adsorption Chemisorption Reactivity (chemistry) 0210 nano-technology Chemical looping combustion |
| Zdroj: | Applied Surface Science. 367:485-492 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2016.01.240 |
| Popis: | The addition of inert support is important for the Cu-based oxygen carrier used in chemical looping combustion (CLC). The effects of the ZrO2 support on the stability and reactivity of Cu-based oxygen carrier were investigated using the density functional theory (DFT). First, the sintering inhibition mechanism of ZrO2 that support active CuO was investigated. The optimized Cu4O4/ZrO2 structure showed a strong interaction occurred between the Cu4O4 cluster and ZrO2(1 0 1) surface. The interaction prevented the migration and agglomeration of CuO. Next, the adsorption of CO on Cu4O4/ZrO2 and the mechanism of the CuO/ZrO2 reduction by CO were studied. CO mainly chemisorbed on the Cu site and ZrO2 acted as an electron donor in the adsorption system. The energy barrier of CuO/ZrO2 reduction by CO (0.79 eV) was much lower than that of the pure CuO cluster (1.44 eV), indicating that ZrO2 had a positive effect on CuO/ZrO2 reduction by CO. After CO was oxidized in the fuel reactor, the CuO was reduced into Cu. The adsorption of O2 on Cu2/ZrO2 and the most likely pathway of Cu2/ZrO2 oxidation by O2 were investigated. The adsorption of O2 was found a strong chemisorption behavior. The energy barriers were low enough for the Cu-based oxygen carrier oxidation reaction. |
| Databáze: | OpenAIRE |
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