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He J, Deng J, Lan T, Liu X, Shen Y, Han L, Wang J, Zhang D. Strong metal oxide-zeolite interactions during selective catalytic reduction of nitrogen oxides. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133164. [PMID: 38103292 DOI: 10.1016/j.jhazmat.2023.133164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/21/2023] [Accepted: 11/30/2023] [Indexed: 12/19/2023]
Abstract
In response to the stricter EU VII emission standards and the "150 ℃ challenge", selective catalytic reduction by ammonia (NH3-SCR) catalysts for motor vehicles are required to achieve high NO conversion below 200 °C. Compounding metal oxides with zeolites is an important strategy to design the low-temperature SCR catalysts. Here, we original prepared Cu-SSZ-13 @ MnGdOx (Cu-Z @ MGO), which achieved over 90% NO conversion and 95% N2 selectivity at 150 ℃. It has been demonstrated that a uniform mesoporous loaded layer of MGO grows on Cu-Z, and a recrystallization zone appears at the MGO-Cu-Z interface. We discover that the excellent low-temperature SCR activity derives from the strong metal oxide-zeolite interaction (SMZI) effects. The SMZI effects cause the anchor and high dispersion of MGO on the surface of Cu-Z. Driven by the SMZI effects, the Mn3+/Mn4+ redox cycle ensures the low and medium temperature-SCR activity and the Cu2+/Cu+ redox cycle guarantees the medium and high temperature-SCR activity. The introduction of MGO improves the reaction activity of -NH2 species adsorbed at Mn sites at 150 ℃, achieving a cycle of reduction and oxidation reactions at low temperatures. This strategy of inducing SMZI effects of metal oxides and zeolites paves a way for development of high-performance catalysts.
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Affiliation(s)
- Jiebing He
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Jiang Deng
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Tianwei Lan
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Xiangyu Liu
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Yongjie Shen
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Lupeng Han
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China
| | - Junan Wang
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China.
| | - Dengsong Zhang
- State Key Laboratory of Advanced Special Steel, Institute of Materials, School of Materials Science and Engineering, International Joint Laboratory of Catalytic Chemistry, College of Sciences, Shanghai University, No.99 Shangda Road, Shanghai 200444, PR China.
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Xu B, Wang Z, Hu J, Zhang L, Zhang Z, Liang H, Zhang Y, Fan G. Dy-Modified Mn/TiO 2 Catalyst Used for the Selective Catalytic Reduction of NO in Ammonia at Low Temperatures. Molecules 2024; 29:277. [PMID: 38202858 PMCID: PMC10781053 DOI: 10.3390/molecules29010277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/23/2023] [Accepted: 01/03/2024] [Indexed: 01/12/2024] Open
Abstract
A novel Mn/TiO2 catalyst, prepared through modification with the rare-earth metal Dy, has been employed for low-temperature selective catalytic reduction (SCR) denitrification. Anatase TiO2, with its large specific surface area, serves as the carrier. The active component MnOx on the TiO2 carrier is modified using Dy. DyxMn/TiO2, prepared via the impregnation method, exhibited remarkable catalytic performance in the SCR of NO with NH3 as the reducing agent at low temperatures. Experiments and characterization revealed that the introduction of a suitable amount of the rare-earth metal Dy can effectively enhance the catalyst's specific surface area and the gas-solid contact area in catalytic reactions. It also significantly increases the concentration of Mn4+, chemisorbed oxygen, and weak acid sites on the catalyst surface. This leads to a notable improvement in the reduction performance of the DyMn/TiO2 catalyst, ultimately contributing to the improvement of the NH3-SCR denitrification performance at low temperatures. At 100 °C and a space velocity of 24,000 h-1, the Dy0.1Mn/TiO2 catalyst can achieve a 98% conversion rate of NOx. Furthermore, its active temperature point decreases by 60 °C after the modification, highlighting exceptional catalytic efficacy at low temperatures. By doubling the space velocity, the NOx conversion rate of the catalyst can still reach 96% at 130 °C, indicating significant operational flexibility. The selectivity of N2 remained stable at over 95% before reaching 240 °C.
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Affiliation(s)
- Bing Xu
- Hubei Provincial Engineering Technology Research Center of Agricultural and Sideline Resources, Chemical Engineering and Utilization, School of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China; (Z.W.); (J.H.); (L.Z.); (Z.Z.); (H.L.); (Y.Z.); (G.F.)
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3
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Wang B, Song K, Li Z, Li K, Shi JW. One-pot synthesis of rare earth modified Cu/SAPO-34 for enhanced selective catalytic reduction denitration performance. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.122281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2022]
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Li Z, Chen G, Shao Z, Zhang H, Guo X. The Effect of Iron Content on the Ammonia Selective Catalytic Reduction Reaction (NH 3-SCR) Catalytic Performance of FeO x/SAPO-34. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:14749. [PMID: 36429468 PMCID: PMC9691003 DOI: 10.3390/ijerph192214749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/02/2022] [Accepted: 11/04/2022] [Indexed: 06/16/2023]
Abstract
Iron-based catalysts are regarded as promising candidates for the ammonia selective catalytic reduction reaction (NH3-SCR) which show good catalytic activity at medium and high temperatures, whereas SAPO-34 molecular sieves have a micro-pore structure and are ideal catalyst carriers. In this paper, four FeOx/SAPO-34 molecular sieve catalysts with different iron contents (Fe = 1%, 2%, 3%, 4%) were prepared using an impregnation method. The effect of iron content on the surface properties and catalytic activity was investigated by a series of characterization techniques including XRD, SEM, BET, XPS, H2-TPR and NH3-TPD. Iron species in the FeOx/SAPO-34 catalysts exist in the form of isolated iron ions or well-dispersed small crystals and iron oxide species clusters. With the addition of iron content, the integrity of CHA (chabazite) zeolite structure remained, but the crystallinity was affected. The FeOx/SAPO-34 catalyst with 3% Fe loading showed a relatively flat surface with no large-diameter particles and strong oxidation-reduction ability. Meanwhile, more acidic sites are exposed, which accelerated the process of catalytic reaction. Thus, the FeOx/SAPO-34 catalyst with 3% Fe showed the best NO conversion performance among the four catalysts prepared and maintained more than 90% NO conversion efficiency in a wide temperature range from 310 °C to 450 °C.
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Affiliation(s)
- Zhaoyang Li
- Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211, China
| | - Geng Chen
- Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211, China
| | - Zhenghua Shao
- Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211, China
| | - Haonan Zhang
- Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211, China
| | - Xiujuan Guo
- School of Civil and Transportation Engineering, Ningbo University of Technology, Ningbo 315211, China
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Qiu S, Xiao Y, Wu H, Lu S, Zhao Q, He G. One-pot synthesis of bimetallic CeCu-SAPO-34 for high-efficiency selective catalytic reduction of nitrogen oxides with NH3 at low temperature. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2022.07.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Li Y, Hou Y, Zhang Y, Yang Y, Huang Z. Confinement of MnO x@Fe 2O 3 core-shell catalyst with titania nanotubes: Enhanced N 2 selectivity and SO 2 tolerance in NH 3- SCR process. J Colloid Interface Sci 2021; 608:2224-2234. [PMID: 34772500 DOI: 10.1016/j.jcis.2021.10.078] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/05/2021] [Accepted: 10/14/2021] [Indexed: 10/20/2022]
Abstract
Surface interface regulation is an important research content in the field of heterogeneous catalysis. To improve the interface interaction between the active component and matrix, tremendous efforts have been dedicated to tailoring the morphology, size, and structure of composite catalysts. In this work, we report a confinement strategy to synthesize a series of core-shell catalysts loaded with metal oxides on titania nanotubes (TNTs), which were applied to the selective catalytic reduction of NOx with ammonia. Interestingly, the core-shell catalyst with confinement of TNTs exhibited the remarkable activity at low temperature region, N2 selectivity and sulfur tolerance. Benefiting from the superior interfacial confinement characteristic of TNTs and Fe2O3, strong component interactions, the surface acid sites and strong oxidizability of MnOx were properly regulated, thus obtained the outstanding activity, N2 selectivity and provide chemical protection to effectively prevent SO2 poisoning. As far as the reaction mechanism, we found that the adsorption and reactivity of Lewis acid sites were the dominant factors affecting the activity in the NH3-SCR process by in situ DRIFT spectra. In general, our work provides an innovative strategy for constructing an TNTs-enwrapped nanocomposite with nano-confinement and core-shell structure to improve the low temperature SCR process.
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Affiliation(s)
- Yifan Li
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yaqin Hou
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China.
| | - Yongzhao Zhang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Yatao Yang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Zhanggen Huang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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Świrk K, Delahay G, Zaki A, Adil K, Cadiau A. Investigation of Mn Promotion on HKUST‐1 Metal‐Organic Frameworks for Low‐Temperature Selective Catalytic Reduction of NO with NH
3. ChemCatChem 2021. [DOI: 10.1002/cctc.202100431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Abdelali Zaki
- ICGM, Univ. Montpellier, CNRS, ENSCM Montpellier France
| | - Karim Adil
- ICGM, Univ. Montpellier, CNRS, ENSCM Montpellier France
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Lin B, Zhang J, Shi H, Chen Z, Jiang B. Mechanism of the hydrocarbon resistance of selective catalytic reduction catalysts supported on different zeolites. Catal Sci Technol 2021. [DOI: 10.1039/d0cy02132f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cu–Mn/SAPO-34 demonstrated excellent HC resistance, NOx complexes and NH3 species could be formed and SCR reaction proceed. While on Cu–Mn/ZSM-5, the active site was occupied by acrylate leading to SCR reaction blocked.
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Affiliation(s)
- Beilong Lin
- School of Environmental Science and Engineering
- Zhejiang Gongshang University
- Hangzhou 310018
- P.R. China
- School of Environment and Energy
| | - Jiawei Zhang
- School of Environmental Science and Engineering
- Zhejiang Gongshang University
- Hangzhou 310018
- P.R. China
| | - Haifeng Shi
- School of Environmental Science and Engineering
- Zhejiang Gongshang University
- Hangzhou 310018
- P.R. China
| | - Ziying Chen
- School of Environmental Science and Engineering
- Zhejiang Gongshang University
- Hangzhou 310018
- P.R. China
| | - Boqiong Jiang
- School of Environmental Science and Engineering
- Zhejiang Gongshang University
- Hangzhou 310018
- P.R. China
- Instrumental Analysis Center of Zhejiang Gongshang University
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9
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DeNOx of Nano-Catalyst of Selective Catalytic Reduction Using Active Carbon Loading MnOx-Cu at Low Temperature. Catalysts 2020. [DOI: 10.3390/catal10010135] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
With the improvement of environmental protection standards, selective catalytic reduction (SCR) has become the mainstream technology of flue gas deNOx. Especially, the low-temperature SCR nano-catalyst has attracted more and more attention at home and abroad because of its potential performance and economy in industrial applications. In this paper, low-temperature SCR catalysts were prepared using the activated carbon loading MnOx-Cu. Then, the catalysts were packed into the fiedbed stainless steel micro-reactor to evaluate the selective catalytic reduction of NO performance. The influence of reaction conditions was investigated on the catalytic reaction, including the MnOx-Cu loading amount, calcination and reaction temperature, etc. The experimental results indicate that SCR catalysts show the highest catalytic activity for NO conversion when the calcination temperature is 350 °C, MnOx loading amount is 5%, Cu loading amount is 3%, and reaction temperature is 200 °C. Under such conditions, the NO conversion arrives at 96.82% and the selectivity to N2 is almost 99%. It is of great significance to investigate the influence of reaction conditions in order to provide references for industrial application.
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