Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst
Nitric oxide (NO) can pose a severe threat to human health and the environment. Many catalytic materials that contain noble metals can oxidize NO into NO<sub>2</sub>. Therefore, the development of a low-cost, earth-abundant, and high-performance catalytic material is essential for NO rem...
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2023-05-01
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| author | Jianlin Yang Lu Zhao Tianran Zhou Shuhua Ma Xiaohui Wang |
| author_facet | Jianlin Yang Lu Zhao Tianran Zhou Shuhua Ma Xiaohui Wang |
| author_sort | Jianlin Yang |
| collection | DOAJ |
| description | Nitric oxide (NO) can pose a severe threat to human health and the environment. Many catalytic materials that contain noble metals can oxidize NO into NO<sub>2</sub>. Therefore, the development of a low-cost, earth-abundant, and high-performance catalytic material is essential for NO removal. In this study, mullite whiskers on a micro-scale spherical aggregate support were obtained from high-alumina coal fly ash using an acid–alkali combined extraction method. Microspherical aggregates and Mn(NO<sub>3</sub>)<sub>2</sub> were used as the catalyst support and the precursor, respectively. A mullite-supported amorphous manganese oxide (MSAMO) catalyst was prepared by impregnation and calcination at low temperatures, in which amorphous MnO<sub>x</sub> is evenly dispersed on the surface and inside of aggregated microsphere support. The MSAMO catalyst, with a hierarchical porous structure, exhibits high catalytic performance for the oxidation of NO. The MSAMO catalyst, with a 5 wt% MnO<sub>x</sub> loading, presented satisfactory NO catalytic oxidation activity at 250 °C, with an NO conversion rate as high as 88%. Manganese exists in a mixed-valence state in amorphous MnO<sub>x</sub>, and Mn<sup>4+</sup> provides the main active sites. The lattice oxygen and chemisorbed oxygen in amorphous MnO<sub>x</sub> participate in the catalytic oxidation of NO into NO<sub>2</sub>. This study provides insights into the effectiveness of catalytic NO removal in practical industrial coal-fired boiler flue gas. The development of high-performance MSAMO catalysts represents an important step towards the production of low-cost, earth-abundant, and easily synthesized catalytic oxidation materials. |
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| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-11T03:32:32Z |
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| spelling | doaj.art-a4e43ed555d0413299cd514857e7f0e82023-11-18T02:16:41ZengMDPI AGMaterials1996-19442023-05-011610382110.3390/ma16103821Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide CatalystJianlin Yang0Lu Zhao1Tianran Zhou2Shuhua Ma3Xiaohui Wang4College of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, ChinaCollege of Materials Science and Engineering, Liaoning Technical University, Fuxin 123000, ChinaSchool of Civil Engineering, Liaoning Technical University, Fuxin 123000, ChinaCAS Key Laboratory for Green Processes and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, ChinaCAS Key Laboratory for Green Processes and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, ChinaNitric oxide (NO) can pose a severe threat to human health and the environment. Many catalytic materials that contain noble metals can oxidize NO into NO<sub>2</sub>. Therefore, the development of a low-cost, earth-abundant, and high-performance catalytic material is essential for NO removal. In this study, mullite whiskers on a micro-scale spherical aggregate support were obtained from high-alumina coal fly ash using an acid–alkali combined extraction method. Microspherical aggregates and Mn(NO<sub>3</sub>)<sub>2</sub> were used as the catalyst support and the precursor, respectively. A mullite-supported amorphous manganese oxide (MSAMO) catalyst was prepared by impregnation and calcination at low temperatures, in which amorphous MnO<sub>x</sub> is evenly dispersed on the surface and inside of aggregated microsphere support. The MSAMO catalyst, with a hierarchical porous structure, exhibits high catalytic performance for the oxidation of NO. The MSAMO catalyst, with a 5 wt% MnO<sub>x</sub> loading, presented satisfactory NO catalytic oxidation activity at 250 °C, with an NO conversion rate as high as 88%. Manganese exists in a mixed-valence state in amorphous MnO<sub>x</sub>, and Mn<sup>4+</sup> provides the main active sites. The lattice oxygen and chemisorbed oxygen in amorphous MnO<sub>x</sub> participate in the catalytic oxidation of NO into NO<sub>2</sub>. This study provides insights into the effectiveness of catalytic NO removal in practical industrial coal-fired boiler flue gas. The development of high-performance MSAMO catalysts represents an important step towards the production of low-cost, earth-abundant, and easily synthesized catalytic oxidation materials.https://www.mdpi.com/1996-1944/16/10/3821high-alumina coal fly ashmullitenitric oxidecatalytic oxidationmanganese oxide |
| spellingShingle | Jianlin Yang Lu Zhao Tianran Zhou Shuhua Ma Xiaohui Wang Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst Materials high-alumina coal fly ash mullite nitric oxide catalytic oxidation manganese oxide |
| title | Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst |
| title_full | Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst |
| title_fullStr | Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst |
| title_full_unstemmed | Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst |
| title_short | Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst |
| title_sort | catalytic oxidation activity of no over mullite supported amorphous manganese oxide catalyst |
| topic | high-alumina coal fly ash mullite nitric oxide catalytic oxidation manganese oxide |
| url | https://www.mdpi.com/1996-1944/16/10/3821 |
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