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Ji W, Jin Q, Xu M, Chen Y, Yang B, Li X, Shen Y, Wang Y, Xu H. Resource utilization of high-concentration SO 2 for sulfur production over La-Ce-O x composite oxide catalyst. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:21756-21768. [PMID: 36279065 DOI: 10.1007/s11356-022-23727-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: 11/22/2021] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
Sulfur dioxide is one of the main causes of air pollution such as acid rain and photochemical smog, and its pollution control and resource utilization have become important research directions. La2O3 was incorporated into CeO2 to enhance the surface basicity of La-Ce-Ox catalyst and increase the concentration of chemisorbed oxygen, thereby promoting the improvement of catalytic performance of SO2 reduction by CO. Results have showed that the incorporation of La2O3 would not only increase the concentration of chemisorbed oxygen and hydroxyl on the catalyst surface, but also increase the basicity of the catalyst, thereby facilitating the adsorption of SO2 on the catalyst surface. The 12%La-Ce-Ox was the optimal catalyst, and its SO2 conversion at 350-400 ℃ reached close to 100%, and the sulfur yield at this temperature range was higher than 93%. Finally, according to the in situ infrared diffuse reflectance spectrum, it was found that the main reaction intermediates of 12%La-Ce-Ox in the catalytic reduction of SO2 were weakly adsorbed sulfate, SO32-, non-coordinating CO32-, monodentate carbonate, and CO, so the catalytic reaction followed the L-H and E-R mechanisms simultaneously.
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Affiliation(s)
- Wenyu Ji
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Qijie Jin
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Mutao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Yingwen Chen
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Bo Yang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, People's Republic of China
| | - Xue Li
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Yuesong Shen
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China
| | - Yan Wang
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Haitao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China.
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Jin Q, Xu M, Lu Y, Yang B, Ji W, Xue Z, Dai Y, Wang Y, Shen Y, Xu H. Simultaneous catalytic removal of NO, mercury and chlorobenzene over WCeMnOx/TiO2-ZrO2: Performance study of microscopic morphology and phase composition. CHEMOSPHERE 2022; 295:133794. [PMID: 35124088 DOI: 10.1016/j.chemosphere.2022.133794] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/06/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Nitrogen oxides, mercury and chlorobenzene are important air pollutants emitted by waste incineration and other industries. Coordinated control of multiple pollutants has become an important technology for air pollution control. Through solid-phase structure control, the catalytic performance of the WCeMnOx/TiO2-ZrO2 catalyst for simultaneous catalytic removal of NO, mercury and simultaneous removal of NO and chlorobenzene were improved. MnWO4 improved the solid acidity of the catalyst and improved the catalytic activity at high temperature. The formation of Ce0·75Zr0·25O2, Ce2WO6, Ce2Zr2O7 and Ce2Ti2O7 improved the catalytic activity at low temperature. The presence of TiOSO4 would affect the valence of metal ions and the reduction of chemisorbed oxygen, thereby reducing the catalytic activity at low temperature. Within the same size range of nanoparticles, cyclic nanoparticles exposed more active sites due to their hollow structure, and their catalytic performance was better than spherical nanoparticles. The thickness of the circular nanoparticles of WCM/TZ-14 catalyst was about 14 nm, and the diameter was about 40 nm Ce0.75Zr0.25O2 and MnWO4 were also present in the phase composition. Therefore, it exhibited the best performance for simultaneous catalytic removal of NO, mercury and simultaneous removal of NO and chlorobenzene. The coincidence temperature window was 347-516 °C. Finally, WCM/TZ-14 catalyst followed both E-R and L-H mechanisms in the NH3-SCR reaction.
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Affiliation(s)
- Qijie Jin
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China; College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
| | - Mutao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China
| | - Yao Lu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China
| | - Bo Yang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, PR China
| | - Wenyu Ji
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China
| | - Zhiwei Xue
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo, 255049, PR China
| | - Yi Dai
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China
| | - Yan Wang
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Yuesong Shen
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
| | - Haitao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing, 210009, PR China.
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Yun J, Tong Z, Hu X, Zhao C, Liu C, Chen D, Zhang H, Chen Z. Modification of CrCeO x with Mo: improved SO 2 resistance and N 2 selectivity for NH 3-SCR at medium–low temperatures. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00679k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mo doping effectively changed the reaction mechanism and surface acidity of CrCeOx catalysts from E–R to L–H, enhancing the sulfur resistance and N2 selectivity.
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Affiliation(s)
- Junge Yun
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
| | - Zhangfa Tong
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Xiaomei Hu
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
| | - Cheng Zhao
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
| | - Chengxian Liu
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
| | - Dingsheng Chen
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
| | - Hanbing Zhang
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Zhihang Chen
- The Key Laboratory of Water and Air Pollution Control of Guangdong Province, Air Pollution Control Engineering Laboratory of Guangdong Province, South China Institute of Environmental Sciences, MEE, Guangzhou 510655, China
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Li C, Han Z, Hu Y, Liu T, Pan X. Synthesis of W-modified CeO 2/ZrO 2 catalysts for selective catalytic reduction of NO with NH 3. RSC Adv 2022; 12:27309-27320. [PMID: 36276006 PMCID: PMC9513439 DOI: 10.1039/d2ra04862k] [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: 08/05/2022] [Accepted: 09/20/2022] [Indexed: 11/30/2022] Open
Abstract
In this paper, a series of tungsten–zirconium mixed binary oxides (denoted as WmZrOx) were synthesized via co-precipitation as supports to prepare Ce0.4/WmZrOx catalysts through an impregnation method. The promoting effect of W doping in ZrO2 on selective catalytic reduction (SCR) performance of Ce0.4/ZrO2 catalysts was investigated. The results demonstrated that addition of W in ZrO2 could remarkably enhance the catalytic performance of Ce0.4/ZrO2 catalysts in a broad temperature range. Especially when the W/Zr molar ratio was 0.1, the Ce0.4/W0.1ZrOx catalyst exhibited the widest active temperature window of 226–446 °C (NOx conversion rate > 80%) and its N2 selectivity was almost 100% in the temperature of 150–450 °C. Moreover, the Ce0.4/W0.1ZrOx catalyst also exhibited good SO2 tolerance, which could maintain more than 94% of NOx conversion efficiency after being exposed to a 100 ppm SO2 atmosphere for 18 h. Various characterization results manifested that a proper amount of W doping in ZrO2 was not only beneficial to enlarge the specific surface area of the catalyst, but also inhibited the growth of fluorite structure CeO2, which were in favor of CeO2 dispersion on the support. The presence of W was conducive to the growth of a stable tetragonal phase crystal of ZrO2 support, and a part of W and Zr combined to form W–Zr–Ox solid super acid. Both of them resulted in abundant Lewis acid sites and Brønsted acid sites, enhancing the total surface acidity, thus significantly improving NH3 species adsorption on the surface of the Ce0.4/W0.1ZrOx catalyst. Furthermore, the promoting effect of adding W on SCR performance was also related to the improved redox capability, higher Ce3+/(Ce3+ + Ce4+) ratio and abundant surface chemisorbed oxygen species. The in situ DRIFTS results indicated that nitrate species adsorbed on the surface of the Ce0.4/W0.1ZrOx catalyst could react with NH3 due to the activation of W. Therefore, the reaction pathway over the Ce0.4/W0.1ZrOx catalyst followed both Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanisms at 250 °C. Interaction of W with Zr improved NH3-SCR performance via enhancing redox and surface acidity.![]()
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Affiliation(s)
- Chenglong Li
- Marine Engineering College, Dalian Maritime University, No.1, Linghai Road, Dalian 116026, China
| | - Zhitao Han
- Marine Engineering College, Dalian Maritime University, No.1, Linghai Road, Dalian 116026, China
| | - Yuqing Hu
- Marine Engineering College, Dalian Maritime University, No.1, Linghai Road, Dalian 116026, China
| | - Tingjun Liu
- Marine Engineering College, Dalian Maritime University, No.1, Linghai Road, Dalian 116026, China
| | - Xinxiang Pan
- Marine Engineering College, Dalian Maritime University, No.1, Linghai Road, Dalian 116026, China
- School of Electronic and Information Technology, Guangdong Ocean University, Zhanjiang 524088, China
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Zheng H, Li R, Zhong C, Li Z, Kang Y, Deng J, Song W, Zhao Z. Theoretical Design of Transition Metal-Doped TiO2 for the Selective Catalytic Reduction of NO with NH3 by DFT Calculations. Catal Sci Technol 2022. [DOI: 10.1039/d1cy02214h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many transition metal oxides supported on TiO2 have been studied for selective catalytic reduction (SCR) of NO with NH3. However, the trade-off exists between the low-temperature activity and N2 selectivity....
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NH3-Selective Catalytic Reduction of NOx to N2 over Ceria Supported WOx Based Catalysts: Influence of Tungsten Content. Catalysts 2021. [DOI: 10.3390/catal11080950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A series of HPW/CeO2 catalysts generated from 12-tungstophosphoric acid, H3PW12O40 (HPW), supported on ceria and presenting different tungsten loadings (2, 4.5, 9, 16, and 40 wt% W) were prepared and characterized by N2 physisorption, XRD, IR, Raman, and UV-Vis. The different characterization techniques suggested that low loading of tungsten resulted in mainly isolated sites, while high tungsten loading produced polymeric or tungsten clusters. Those materials exhibited high activity in NH3-SCR of NOx into N2. Moreover, the series of experiments indicated that low loading in tungsten (2% HPW/CeO2) displayed the highest activity with a remarkable N2 selectivity (99%) at medium-high temperature (300–515 °C), owing to the high amount of monomeric tungstate coverage on the catalyst surface.
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Yang L, Lu B, Ge Z, Jin Q, Shen Y. Ammonia storage/release behaviors of the CeSn0.2Mo0.6Ox/TiO2 catalyst in selective catalytic reduction of NO. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Vedagiri P, Martin LJ, Varuvel EG. Characterization of urea SCR using Taguchi technique and computational methods. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:11988-11999. [PMID: 32306257 DOI: 10.1007/s11356-020-08743-y] [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: 11/13/2019] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Use of biodiesel in diesel engine helps to reduce HC, CO, and smoke emissions due to their enormous oxygen content, whereas NOx emissions formed by Zeldovich mechanism shoot up. Implementation of Bharat Stage (BS) VI by April 2020 in India has created extreme pressure on automobile manufacturers to include after treatment technology in their systems. Selective catalytic reduction (SCR), a NOx control technology, is operated using aqueous urea solution as the reductant. There are several parameters that need to be monitored to enhance the NOx conversion efficiency of SCR retrofit. The uniformity index of ammonia, which determines the conversion efficiency, is greatly influenced by parameters like exhaust gas temperature, injection angle, injector position, mass flow rate, and SCR geometry. This paper considers two types of SCR design, namely SCR with and without mixer design and their impact on NOx reduction. The effect of mass flow rate on urea conversion in SCR design without mixer is 27%, but the impact is reduced greatly in SCR design with mixer with less than 2% variation. The UI resulting from different cases ranges from 0.59 to 0.83. Using Taguchi technique and CFD tool, the impact of parameters on both the SCR designs has been investigated and the optimum SCR design is reported.
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Affiliation(s)
- Praveena Vedagiri
- Department of Mechanical Engineering, SRM University, Kattankulathur, 603203, India.
| | - Leenus Jesu Martin
- Department of Automobile Engineering, SRM University, Kattankulathur, 603203, India
| | - Edwin Geo Varuvel
- Department of Automobile Engineering, SRM University, Kattankulathur, 603203, India
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Jin Q, Lu Y, Ji W, Yang B, Xu M, Xue Z, Dai Y, Xu H. Selective catalytic reduction of NO over W–Zr-O x/TiO 2: performance study of hierarchical pore structure. RSC Adv 2021; 11:33361-33371. [PMID: 35497562 PMCID: PMC9042316 DOI: 10.1039/d1ra05801k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 09/29/2021] [Indexed: 12/17/2022] Open
Abstract
A series of W–Zr-Ox/TiO2 catalysts with hierarchical pore structure were prepared and used for selective catalytic reduction of NO by NH3.
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Affiliation(s)
- Qijie Jin
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
| | - Yao Lu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
| | - Wenyu Ji
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
| | - Bo Yang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, PR China
| | - Mutao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
| | - Zhiwei Xue
- School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo, 255049, PR China
| | - Yi Dai
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
| | - Haitao Xu
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 210009, PR China
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