Synthesis of bulk vanadium oxide with a large surface area using organic acids and its low-temperature NH3-SCR activity
| Autor: | Toru Murayama, Kazuhiro Yoshida, Keiichiro Morita, Eiji Kiyonaga, Shinichi Hata, Masatake Haruta, Yusuke Inomata |
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| Rok vydání: | 2021 |
| Předmět: |
inorganic chemicals
chemistry.chemical_classification Carboxylic acid Oxalic acid 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis Vanadium oxide 0104 chemical sciences chemistry.chemical_compound Ammonium metavanadate chemistry Succinic acid Malic acid 0210 nano-technology Nuclear chemistry Organic acid |
| Zdroj: | Catalysis Today. 376:188-196 |
| ISSN: | 0920-5861 |
| Popis: | Selective catalytic reduction using NH3 (NH3-SCR) is a chemical process that is used for the elimination of NOx (NO and NO2). Although current vanadia-based catalysts need a high reaction temperature, which leads to deactivation of the catalysts, bulk vanadium oxide showed the potential for NH3-SCR at a low temperature below 150 °C. We investigated a method for synthesis of vanadium oxide with a large surface area using an organic acid to enhance its NH3-SCR activity. Vanadium oxide catalysts were synthesized from ammonium metavanadate (NH4VO3) and organic acids (oxalic acid, succinic acid, malic acid and citric acid). When carboxylic acids (oxalic acid and succinic acid) were used as the organic acid source, the surface area of the catalysts increased up to 41 cm2 g−1, which was larger than that of vanadium oxide synthesized without an organic acid and with hydroxy acid. SEM and TEM measurements showed that vanadium oxide catalysts synthesized by the calcination of vanadyl oxalate at 300 °C (V2O5-OX_300) formed a pore structure that contributed to the increase in surface area. An increase in the number of acid sites and redox sites, which is important for NH3-SCR to proceed, was confirmed from NH3-TPD and H2-TPR measurements for V2O5-OX_300. The NO conversion of V2O5-OX_300 (47 % at 100 °C) was higher than that of the catalysts synthesized from only NH4VO3 (19 % at 100 °C), indicating that vanadium oxide catalysts synthesized using carboxylic acid have the low-temperature NH3-SCR activity due to the increase in their surface area. |
| Databáze: | OpenAIRE |
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