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Cheng T, Du B, Zhou H, Jiang Z, Xie Q, Zhu C. Tungsten modified natural limonite catalyst for efficient low-temperature selective catalytic reduction of NO removal with NH 3: preparation and characterization. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:36294-36310. [PMID: 36547828 DOI: 10.1007/s11356-022-24755-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
With natural limonite as the precursor and an ammonium tungstate hydrate as modification, the W/limonite composite catalysts were synthesized by the impregnation method. Their structures and properties were systematically characterized and analyzed; the denitrification activity and resistance to water and sulfur on catalysts were investigated. The results indicated that the W/limonite composite with W/Fe mass ratio of 9% and calcination temperature of 300 °C had highly catalytic activity, enhanced resistance to sulfur and water. The NO conversion efficiency was maintained over 85% with NO initial concentration of 500 ppm, the gas hourly space velocity (GHSV) of 36,000 h-1, and reaction temperature of 100 °C, while it was greater than 98% with addition of 200 ppm SO2 and 3 vol. % H2O at the reaction temperature of 250 °C. The superior performance was mainly ascribed to the formation of W-OH species and W = O species with wide dispersion on the surface of goethite or in Fe2O3 lattice defects, to generate more acidic hydroxyl groups and more oxygen defects and strong acidity Brønsted for the SCR reaction.
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Affiliation(s)
- Ting Cheng
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Bo Du
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Huimin Zhou
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Zhaozhong Jiang
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Qiaoqin Xie
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China
| | - Chengzhu Zhu
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, 230009, People's Republic of China.
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, 230009, People's Republic of China.
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, 230009, People's Republic of China.
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Du B, Hu Y, Cheng T, Jiang Z, Wang Z, Zhu C. Low-temperature selective catalytic reduction of NO with NH 3 over an FeO x /β-MnO 2 composite. RSC Adv 2023; 13:6378-6388. [PMID: 36845597 PMCID: PMC9943891 DOI: 10.1039/d3ra00235g] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 02/13/2023] [Indexed: 02/24/2023] Open
Abstract
A series of Fe-modified β-MnO2 (FeO x /β-MnO2) composite catalysts were prepared by an impregnation method with β-MnO2 and ferro nitrate as raw materials. The structures and properties of the composites were systematically characterized and analyzed by X-ray diffraction, N2 adsorption-desorption, high-resolution electron microscopy, temperature-programmed reduction of H2, temperature-programmed desorption of NH3, and FTIR infrared spectroscopy. The deNO x activity, water resistance, and sulfur resistance of the composite catalysts were evaluated in a thermally fixed catalytic reaction system. The results indicated that the FeO x /β-MnO2 composite (Fe/Mn molar ratio of 0.3 and calcination temperature of 450 °C) had higher catalytic activity and a wider reaction temperature window compared with β-MnO2. The water resistance and sulfur resistance of the catalyst were enhanced. It reached 100% NO conversion efficiency with an initial NO concentration of 500 ppm, a gas hourly space velocity of 45 000 h-1, and a reaction temperature of 175-325 °C. The appropriate Fe/Mn molar ratio sample had a synergistic effect, affecting the morphology, redox properties, and acidic sites, and helped to improve the low-temperature NH3-SCR activity of the composite catalyst.
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Affiliation(s)
- Bo Du
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China
| | - Yuting Hu
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China
| | - Ting Cheng
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China
| | - Zhaozhong Jiang
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China
| | - Zhenzhen Wang
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China
| | - Chengzhu Zhu
- School of Resource and Environmental Engineering, Hefei University of Technology Hefei 230009 P. R. China +86 551 62901649 +86 551 62901523.,Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology Hefei 230009 P. R. China.,Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology Hefei 230009 P. R. China.,Low Temperature Denitration Engineering Research Center of Anhui Province Hefei 230001 P. R. China
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Luo L, Huang B, Shi Z, Wen Z, Li W, Zi G, Yang L. CO + NH 3 coupling denitration at low temperatures over manganese/activated carbon catalysts. RSC Adv 2022; 12:34236-34244. [PMID: 36545625 PMCID: PMC9709521 DOI: 10.1039/d2ra06429d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 11/23/2022] [Indexed: 12/03/2022] Open
Abstract
To explore the mechanism of low-temperature carbon monoxide and ammonia (CO + NH3) coupling denitration of manganese/activated carbon (Mn/AC) catalysts, Mn/AC series catalysts were prepared using the impregnation method with AC activated by nitric acid as a precursor and manganese nitrate as a precursor. We characterized the surface morphology, pore structure, active component phase, functional group, and active component valence change law of the Mn/AC catalyst. The denitration rate order with different Mn loadings is 7Mn/AC > 9Mn/AC > 5Mn/AC. When the Mn loading was 7%, the catalyst's surface was smooth, with a good pore structure and uniform surface distribution of metal particles. These features increased the reacting gas's contact area, improving the denitration rate. The reason for this was oxygen chemisorption on the catalyst's surface. The Mn4+ and the number of oxygen-containing functional groups on the catalyst surface increase after Mn loading increases; this provides more active sites for denitration and promotes the reaction's conversion to fast selective catalytic reduction. The low-temperature CO + NH3 coupling denitration of Mn/AC catalysts conforms to the Langmuir-Hinshelwood mechanism when the temperature is lower than 230 °C and the Eley-Rideal mechanism when the temperature is higher than 230 °C. The research results can provide new ideas for low-temperature flue gas denitration.
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Affiliation(s)
- Liubin Luo
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Bangfu Huang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Zhe Shi
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Zhenjing Wen
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Wanjun Li
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Gaoyong Zi
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China,Clean Metallurgy Key Laboratory of Complex Iron Resources, University of Yunnan ProvinceKunming 650093China
| | - Linjing Yang
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and TechnologyKunming650093China
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Xie J, Li M, Wu Z, Zeng Y, Zhang S, Liu J, Zhong Q. Effect of pre-oxidation process on V 2O 5/AC catalyst for the selective catalytic reduction of NO x with NH 3. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:13534-13540. [PMID: 34595700 DOI: 10.1007/s11356-021-16491-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Activated coke-based catalysts have attracted extensive attention in denitration by selective catalytic reduction by NH3 (NH3-SCR), due to their excellent catalytic performance at low temperature. In the paper, the V2O5/AC catalyst was prepared by the impregnation method to investigate the effect of pre-oxidation process on its NH3-SCR activity. Activity test results show that the V2O5/AC catalyst with 4-h pre-oxidation exhibits the best NOx removal efficiency, which reaches the NOx conversion is over 75% in the range of 200-240 °C and exhibits an excellent resistance to SO2 and H2O. Characterization results demonstrate that the V4+ was oxidized by oxygen molecule during pre-oxidation process, which contributes to the formation of V5+ ions and surface-active oxygen species. The surface-active oxygen species are conducive to promoting the "fast SCR" reaction; thus, the pre-oxidized process can contribute to the superior NH3-SCR performance for V2O5/AC catalyst at low temperature.
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Affiliation(s)
- Jiahua Xie
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Mengyu Li
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Zihua Wu
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Yiqing Zeng
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China
| | - Shule Zhang
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China.
| | - Jing Liu
- Shanghai Clear Science & Technology Co. Ltd, Nanjing, 210008, People's Republic of China
| | - Qin Zhong
- School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, People's Republic of China.
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Xu Q, Li Z, Wang L, Zhan W, Guo Y, Guo Y. Understand the role of redox property and NO adsorption over MnFeOx for NH3-SCR. Catal Sci Technol 2022. [DOI: 10.1039/d1cy02203b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Widening the operation temperature window of selective catalytic reduction NO by NH3 (NH3-SCR) is a challenge to meet the increasingly stringent emission control regulations of NOx. Hence, MnFeOx with different...
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Promotional Effect of Manganese on Selective Catalytic Reduction of NO by CO in the Presence of Excess O2 over M@La–Fe/AC (M = Mn, Ce) Catalyst. Catalysts 2020. [DOI: 10.3390/catal10111322] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The catalytic performance of a series of La-Fe/AC catalysts was studied for the selective catalytic reduction (SCR) of NO by CO. With the increase in La content, the Fe2+/Fe3+ ratio and amount of surface oxygen vacancies (SOV) in the catalysts increased; thus the catalytic activity improved. Incorporating the promoters to La3-Fe1/active carbon (AC) catalyst could affect the catalyst activity by changing the electronic structure. The increase in Fe2+/Fe3+ ratio after the promoter addition is possibly due to the extra synergistic interaction of M (Mn and Ce) and Fe through the redox equilibrium of M3+ + Fe3+ ↔ M4+ + Fe2+. This phenomenon could have improved the redox cycle, enhanced the SOV formation, facilitated NO decomposition, and accelerated the CO-SCR process. The presence of O2 enhanced the formation of the C(O) complex and improved the activation of the metal site. Mn@La3-Fe1/AC catalyst revealed an excellent NO conversion of 93.8% at 400 °C in the presence of 10% oxygen. The high catalytic performance of MnOx and double exchange behavior of Mn3+ and Mn4+ can increase the number of SOV and improve the catalytic redox properties.
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Li X, Li Q, Li W, Zhang X, Zhong L, Zhang C, Fang Q, Chen G. Enhancement of SCR performance of monolithic Mn–Ce/Al
2
O
3
/cordierite catalysts by using modified deposition precipitation method. ASIA-PAC J CHEM ENG 2019. [DOI: 10.1002/apj.2318] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xin Li
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Quan Li
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Wei Li
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Xiaopei Zhang
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Liu Zhong
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Cheng Zhang
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Qingyan Fang
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
| | - Gang Chen
- State Key Laboratory of Coal CombustionHuazhong University of Science and Technology Wuhan China
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