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Xiong Z, Zhu Y, Liu J, Du Y, Zhou F, Jin J, Yang Q, Lu W. The influence of H 2O or/and O 2 introduction during the low-temperature gas-phase sulfation of organic COS + CS 2 on the conversion and deposition of sulfur-containing species in the sulfated CeO 2-OS catalyst for NH 3-SCR. NANOSCALE 2024; 16:1223-1237. [PMID: 38115815 DOI: 10.1039/d3nr04686a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Herein, the typical components of blast furnace gas, including H2O and O2, were introduced to improve the NH3-SCR activity of the sulfated CeO2-OS catalyst during the gas-phase sulfation of organic COS + CS2 at 50 °C. The characterization results demonstrate that the introduction of O2 or H2O during gas-phase sulfation enhances the conversion of organic COS + CS2 on a cubic fluorite CeO2 surface and reduces the formation of sulfur and sulfates in the catalyst, but decreases the BET surface area and pore volume of the sulfated CeO2-OS catalyst. However, the introduction of O2 or H2O during the gas-phase sulfation increases the molar ratios of Ce3+/(Ce3+ + Ce4+) and Oβ/(Oα + Oβ + Oγ) on the sulfated CeO2-OS catalyst surface, thus promoting the formation of surface oxygen vacancies and chemisorbed oxygen, and these properties of the catalyst are further enhanced by the co-existence of O2 and H2O. Furthermore, the reduction of sulfates formed under the action of O2 or H2O decreases the weak acid sites of the sulfated CeO2-OS catalyst, but the few and highly dispersive sulfates present stronger reducibility, and the proportion of medium-strong acid sites of the catalyst increases. These factors help to improve the NH3-SCR activity of the sulfated CeO2-OS catalyst. Thus, there exists a synergistic effect of H2O and O2 introduction during gas-phase sulfation on the physical-chemical properties and catalytic performance of the sulfated CeO2-OS catalyst by organic COS + CS2 at 50 °C.
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Affiliation(s)
- Zhibo Xiong
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
| | - Yafei Zhu
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
| | - Jiaxing Liu
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
| | - Yanping Du
- School of Engineering, Lancaster University, Lancaster, LA1 4YW, UK
| | - Fei Zhou
- Jiangsu Guoxin Jingjiang Power Co. Ltd., Jingjiang 214500, Jiangsu, China
| | - Jing Jin
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
| | - Qiguo Yang
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
| | - Wei Lu
- School of Energy and Power Engineering, University of Shanghai for Science & Technology, Shanghai, 200093, China.
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Hong J, Zou X, Qin Z, Zhou B, Geng S, Zhang Y, Zou X, Lu X. Effect of CO 2 on the Desulfurization of Sintering Flue Gas with Hydrated Lime. MATERIALS (BASEL, SWITZERLAND) 2022; 16:303. [PMID: 36614643 PMCID: PMC9821830 DOI: 10.3390/ma16010303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/01/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
The effect of carbon dioxide (CO2) on the desulfurization of sintering flue gas with hydrate (Ca(OH)2) as an absorbent was investigated, and the formation of calcium carbonate (CaCO3) and its effect on the desulfurization was discussed. The competitive relationship between carbon dioxide (CO2) and sulfur dioxide (SO2) with the deacidification agent in sintering flue gas is discussed thermodynamically, showing that sulfates are more likely to be generated under high oxygen potential conditions and that SO2 reacts more preferentially than CO2 under a thermodynamic standard state. The amount of produced CaCO3 increases under the condition that the CO2 concentration is absolutely dominant to SO2 in the sintering flue gas atmosphere. The effect of temperature, humidity and CO2 concentration on the desulfurization of Ca(OH)2 are discussed experimentally. The increasing temperature is not conducive to desulfurization, and the humidity can promote desulfurization, while excessive humidity could inhibit desulfurization. The suitable relative humidity is 20%. In situ generated calcium carbonate has a certain desulfurization effect, but the desulfurization effect is not as good as Ca(OH)2. However, a large proportion of CaCO3 was produced in the desulfurization ash under the condition that CO2 concentration was absolutely dominant to SO2 in the sintering flue gas atmosphere.
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Affiliation(s)
- Jianguo Hong
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
- Ironmaking Plant, Shanghai Meishan Iron and Steel Co., Ltd., Nanjing 210039, China
| | - Xinqing Zou
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Ziqiang Qin
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Bin Zhou
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Shuhua Geng
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Yuwen Zhang
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Xingli Zou
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Xionggang Lu
- State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy & School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
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Wang F, Wang C, Zhao K, Shan Y, Ma Y, Wang C, Li Z, Sun X, Li K, He H, Ning P. The design of the highly active NH3-SCR catalyst Ce-W/UiO-66: Close Coupling of Active Sites and Acidic Sites. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ce1−xFexVO4 with Improved Activity for Catalytic Reduction of NO with NH3. Catalysts 2022. [DOI: 10.3390/catal12050549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A series of Ce1−xFexVO4 (x = 0, 0.25, 0.50, 0.75, 1) catalysts prepared by modified hydrothermal synthesis were used for selective catalytic reduction (SCR) of NOx with NH3. Among them, Ce0.5Fe0.5VO4 showed the highest catalytic activity. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction using H2 (H2-TPR), and temperature-programmed desorption of NH3 (NH3-TPD). The results indicated the formation of Ce-Fe-V-O solid solutions. The average oxidation states (AOS) of Ce, Fe, V, and O atoms changed obviously with the incorporation of Fe3+ into CeVO4, and the acidity of Ce0.5Fe0.5VO4 differs from that of CeVO4 and FeVO4. The presence of more acid sites and a sharp increase in active oxygen species in Ce0.5Fe0.5VO4 effectively improved the selective catalytic reduction (SCR) activity.
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Fang X, Qu W, Qin T, Hu X, Chen L, Ma Z, Liu X, Tang X. Abatement of Nitrogen Oxides via Selective Catalytic Reduction over Ce 1-W 1 Atom-Pair Sites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6631-6638. [PMID: 35500091 DOI: 10.1021/acs.est.2c00482] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Environmentally benign CeO2-WO3/TiO2 catalysts are promising alternatives to commercial toxic V2O5-WO3/TiO2 for controlling NOx emission via selective catalytic reduction (SCR), but the insufficient catalytic activity of CeO2-WO3/TiO2 catalysts is one of the obstacles in their applications because of a lack of an in-depth understanding of the CeO2-WO3 interactions. Herein, we design a Ce1-W1/TiO2 model catalyst by anchoring Ce1-W1 atom pairs on anatase TiO2(001) to investigate the synergy between Ce and W in SCR. A series of characterizations combined with density functional theory calculations and in situ diffuse-reflectance infrared Fourier-transform experiments reveal that there exists a strong electronic interaction within Ce1-W1 atom pairs, leading to a much better SCR performance of Ce1-W1/TiO2 compared with that of Ce1/TiO2 and W1/TiO2. The Ce1-W1 synergy not only shifts down the lowest unoccupied states of Ce1 near the Fermi level, thus enhancing the abilities in adsorbing and oxidizing NH3 but also makes the frontier orbital electrons of W1 delocalized, thus accelerating the activation of O2. The deep insight of the Ce-W synergy may assist in the design and development of efficient catalysts with an SCR activity as high as or even higher than V2O5-WO3/TiO2.
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Affiliation(s)
- Xue Fang
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Weiye Qu
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Tian Qin
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaolei Hu
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Liwei Chen
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhen Ma
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xi Liu
- School of Chemistry and Chemical Engineering, In Situ Center for Physical Science, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xingfu Tang
- Department of Environmental Science & Engineering, Fudan University, 2005 Songhu Road, Shanghai 200438, China
- Jiangsu Collaborative Innovation Center of Atmospheric Environment & Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Xiong ZB, Li ZZ, Du YP, Li CX, Lu W, Tian SL. Starch bio-template synthesis of W-doped CeO 2 catalyst for selective catalytic reduction of NO x with NH 3: influence of ignition temperature. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:5914-5926. [PMID: 32979181 DOI: 10.1007/s11356-020-10888-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/15/2020] [Indexed: 06/11/2023]
Abstract
A novel tungsten-doped CeO2 catalyst was fabricated via the sweet potato starch bio-template spread self-combustion (SSC) method to secure a high NH3-SCR activity. The study focuses on the influence of ignition temperature on the physical structure and redox properties of the synthesized catalyst and the catalytic performance of NOx reduction with NH3. These were quantitatively examined by conducting TG-DSC measurements of the starch gel, XRD analysis for the crystallites, SEM and TEM assessments for the morphology of the catalyst, XPS and H2-TPR measurements for the distribution of cerium and tungsten, and NH3-TPD assessments for the acidity of the catalyst. It is found that the ignition temperature shows an important role in the interaction of cerium and tungsten species, and the optimal ignition temperature is 500 °C. The increase of ignition temperature from 150 °C is beneficial to the interactions of species in the catalyst, depresses the formation of WO3, and refines the cubic CeO2 crystallite. The sample ignited at 500 °C shows the biggest BET surface area, the highest surface concentration of Ce species and molar ratio of Ce3+/(Ce3++Ce4+), and the most abundant surface Brønsted acid sites, which are the possible reasons for the superiority of the NH3-SCR activity. With a high GHSV of 200,000 mL (g h)-1 and the optimal ignition temperature, Ce4W2Oz-500 can achieve a steadily high NOx reduction of 80% or more at a lowered reduction temperature in the range of 250~500 °C.
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Affiliation(s)
- Zhi-Bo Xiong
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
- Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China.
| | - Zhen-Zhuang Li
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Yan-Ping Du
- China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Cheng-Xu Li
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Wei Lu
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
- Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
| | - Su-Le Tian
- School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, 200093, China
- Shandong Electric Power Engineering Consulting Institute Corp., Ltd, Jinan, 250013, China
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Promotional Effects on NH3-SCR Performance of CeO2–SnO2 Catalysts Doped by TiO2: A Mechanism Study. CATALYSIS SURVEYS FROM ASIA 2021. [DOI: 10.1007/s10563-020-09318-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Guo J, Zhang G, Tang Z, Zhang J. Morphology-Controlled Synthesis of TiO2 with Different Structural Units and Applied for the Selective Catalytic Reduction of NOx with NH3. CATALYSIS SURVEYS FROM ASIA 2020. [DOI: 10.1007/s10563-020-09312-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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