Influence of thermal treatment conditions on the characteristics of Cu-based metal oxides derived from hydrotalcite-like compounds and their performance in bio-ethanol dehydrogenation to acetaldehyde
| Autor: | Victor Teixeira da Silva, Cristiane A. Henriques, Cristiane B. Rodella, Zilacleide S.B. Sousa, Ivone Sampaio Pereira Campisano |
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| Rok vydání: | 2018 |
| Předmět: |
Hydrotalcite
Thermal decomposition Inorganic chemistry Acetaldehyde chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Decomposition Copper Catalysis 0104 chemical sciences chemistry.chemical_compound chemistry Mixed oxide Dehydrogenation 0210 nano-technology |
| Zdroj: | Catalysis Today. 306:111-120 |
| ISSN: | 0920-5861 |
| DOI: | 10.1016/j.cattod.2017.03.017 |
| Popis: | The influence of the copper presence on the active sites of catalysts derived from a hydrotalcite-like compound (HTLC) was investigated in bio-ethanol dehydrogenation. It was observed that the presence of copper lead to an inhibition of dehydration and coupling reactions that occurred on the mixed oxide (MgAlOx) obtained by thermal decomposition of the HTCL, leading to selective formation of acetaldehyde. In situ X-ray absorption experiments revealed that the nature of the copper species depended on the nature of the atmosphere used to promote the HTCL decomposition: when the decomposition was conducted under helium atmosphere at 750 °C a mixture of Cu0/Cu+1 species was formed, while when the decomposition was done under an oxygen/helium atmosphere there was only the presence of Cu+2 species. Because the mixed oxide formed after thermal decomposition of the HTCL presents activity for bio-ethanol dehydration, coupling and dehydrogenation reactions, on the studied systems the bio-ethanol conversion into acetaldehyde does not seem to be influenced by the different copper species, even though it is well known that Cu0 and Cu+1 sites are necessary for the reaction. |
| Databáze: | OpenAIRE |
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