Integrated In Situ Characterization of a Molten Salt Catalyst Surface: Evidence of Sodium Peroxide and Hydroxyl Radical Formation
| Autor: | Abdulaziz M Khan, Ayman El-Baz, S. Mani Sarathy, Yu Tang, Kazuhiro Takanabe, Luan Nguyen, Benjamin W. Jacobs, Franklin Feng Tao, Ahmed Ziani |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Radical
Inorganic chemistry sodium peroxide 02 engineering and technology 010402 general chemistry Photochemistry 01 natural sciences oxidative coupling Catalysis chemistry.chemical_compound X-ray photoelectron spectroscopy Molten salt 010405 organic chemistry hydroxyl radicals Communication Sodium peroxide General Medicine General Chemistry 021001 nanoscience & nanotechnology Communications 0104 chemical sciences chemistry Heterogeneous Catalysis Melting point ambient-pressure XPS Oxidative coupling of methane Hydroxyl radical 0210 nano-technology |
| Zdroj: | Angewandte Chemie (International Ed. in English) |
| ISSN: | 1521-3773 1433-7851 |
| Popis: | Sodium‐based catalysts (such as Na2WO4) were proposed to selectively catalyze OH radical formation from H2O and O2 at high temperatures. This reaction may proceed on molten salt state surfaces owing to the lower melting point of the used Na salts compared to the reaction temperature. This study provides direct evidence of the molten salt state of Na2WO4, which can form OH radicals, using in situ techniques including X‐ray diffraction (XRD), scanning transmission electron microscopy (STEM), laser induced fluorescence (LIF) spectrometry, and ambient‐pressure X‐ray photoelectron spectroscopy (AP‐XPS). As a result, Na2O2 species, which were hypothesized to be responsible for the formation of OH radicals, have been identified on the outer surfaces at temperatures of ≥800 °C, and these species are useful for various gas‐phase hydrocarbon reactions, including the selective transformation of methane to ethane. |
| Databáze: | OpenAIRE |
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