1
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Negri C, Usberti N, Contaldo G, Bracconi M, Nova I, Maestri M, Tronconi E. Quantitative Kinetic Insights from Operando-UV/Vis Spectroscopy: An Application to NH 3-SCR of NOx on Cu-CHA Catalysts. Angew Chem Int Ed Engl 2024:e202408328. [PMID: 38829015 DOI: 10.1002/anie.202408328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/01/2024] [Accepted: 06/01/2024] [Indexed: 06/05/2024]
Abstract
We employ UV/Vis Diffuse Reflectance spectroscopy directly coupled with a packed bed flow reactor to extract quantitative kinetic information. We use as a show-case the CuII/CuI redox dynamics during the reduction half cycle of the NH3-Selective Catalytic Reduction (SCR) on Cu-CHA catalysts. Our measurements enable quantification of the fraction of oxidized Cu, reconstructed by Multivariate Curve Resolution (MCR) together with monitoring of the gas-phase evolution during the reaction. These data both on the dynamics of the gas-phase and of the active site oxidation state have been used to assess the reduction half cycle rate equation and estimate the rate constant. Our results in terms of reaction orders and kinetic constant are in line with previous findings in the literature. Overall, our results demonstrate that the combined analysis of the UV spectra and of the gas-phase dynamics provides converging and unparalleled kinetic insight: this approach effectively resolves ambiguities concerning RHC kinetics and mechanism. More in general, this work provides evidence that operando spectroscopy can be used to extract quantitative kinetic information on catalytic cycles.
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Affiliation(s)
- Chiara Negri
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Nicola Usberti
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Gabriele Contaldo
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Mauro Bracconi
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Isabella Nova
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Matteo Maestri
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
| | - Enrico Tronconi
- Laboratory of Catalysis and Catalytic Processes, Dipartimento di Energia, Politecnico di Milano, Via La Masa 34, 20156, Milano, Italy
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2
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Wu Y, Zhao W, Ahn SH, Wang Y, Walter ED, Chen Y, Derewinski MA, Washton NM, Rappé KG, Wang Y, Mei D, Hong SB, Gao F. Interplay between copper redox and transfer and support acidity and topology in low temperature NH 3-SCR. Nat Commun 2023; 14:2633. [PMID: 37149681 PMCID: PMC10164144 DOI: 10.1038/s41467-023-38309-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 04/25/2023] [Indexed: 05/08/2023] Open
Abstract
Low-temperature standard NH3-SCR over copper-exchanged zeolite catalysts occurs on NH3-solvated Cu-ion active sites in a quasi-homogeneous manner. As key kinetically relevant reaction steps, the reaction intermediate CuII(NH3)4 ion hydrolyzes to CuII(OH)(NH3)3 ion to gain redox activity. The CuII(OH)(NH3)3 ion also transfers between neighboring zeolite cages to form highly reactive reaction intermediates. Via operando electron paramagnetic resonance spectroscopy and SCR kinetic measurements and density functional theory calculations, we demonstrate here that such kinetically relevant steps become energetically more difficult with lower support Brønsted acid strength and density. Consequently, Cu/LTA displays lower Cu atomic efficiency than Cu/CHA and Cu/AEI, which can also be rationalized by considering differences in their support topology. By carrying out hydrothermal aging to eliminate support Brønsted acid sites, both CuII(NH3)4 ion hydrolysis and CuII(OH)(NH3)3 ion migration are hindered, leading to a marked decrease in Cu atomic efficiency for all catalysts.
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Affiliation(s)
- Yiqing Wu
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Wenru Zhao
- School of Materials Science and Engineering, Tiangong University, Tianjin, 300387, China
| | - Sang Hyun Ahn
- Center for Ordered Nanoporous Materials Synthesis, Division of Environmental Science and Engineering, POSTECH, Pohang, 37673, Republic of Korea
| | - Yilin Wang
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Eric D Walter
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Ying Chen
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Miroslaw A Derewinski
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
- J. Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, 30-239, Krakow, Poland
| | - Nancy M Washton
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Kenneth G Rappé
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
| | - Yong Wang
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, 99163, US
| | - Donghai Mei
- School of Materials Science and Engineering, Tiangong University, Tianjin, 300387, China.
- School of Environmental Science and Engineering, Tiangong University, Tianjin, 300387, China.
| | - Suk Bong Hong
- Center for Ordered Nanoporous Materials Synthesis, Division of Environmental Science and Engineering, POSTECH, Pohang, 37673, Republic of Korea.
| | - Feng Gao
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA, 99354, US.
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3
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Chen J, Shan Y, Sun Y, Ding W, Xue S, Han X, Du J, Yan Z, Yu Y, He H. Hydrothermal Aging Alleviates the Phosphorus Poisoning of Cu-SSZ-39 Catalysts for NH 3-SCR Reaction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4113-4121. [PMID: 36811527 DOI: 10.1021/acs.est.2c08876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
As a new type of catalyst with the potential for commercial application in NOx removal from diesel engine exhausts, Cu-SSZ-39 catalysts must have excellent resistance to complex and harsh conditions. In this paper, the effects of phosphorus on Cu-SSZ-39 catalysts before and after hydrothermal aging treatment were investigated. Compared with fresh Cu-SSZ-39 catalysts, phosphorus poisoning significantly decreased the low-temperature NH3-SCR catalytic activity. However, such activity loss was alleviated by further hydrothermal aging treatment. To reveal the reason for this interesting result, a variety of characterization techniques including NMR, H2-TPR, X-ray photoelectron spectroscopy, NH3-TPD, and in situ DRIFTS measurements were employed. It was found that Cu-P species produced by phosphorus poisoning decreased the redox ability of active copper species, resulting in the observed low-temperature deactivation. After hydrothermal aging treatment, however, Cu-P species partly decomposed with the formation of active CuOx species and a release of active copper species. As a result, the low-temperature NH3-SCR catalytic activity of Cu-SSZ-39 catalysts was recovered.
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Affiliation(s)
- Junlin Chen
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yu Sun
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenqing Ding
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, China
| | - Sen Xue
- Weichai Power Co., Ltd., Weifang 261061, China
| | - Xuewang Han
- Weichai Power Co., Ltd., Weifang 261061, China
| | - Jinpeng Du
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Zidi Yan
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
| | - Yunbo Yu
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- School of Rare Earths, University of Science and Technology of China, Hefei 230026, China
- Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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4
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Xiong W, Liu L, Guo A, Chen D, Shan Y, Fu M, Wu J, Ye D, Chen P. Economical and Sustainable Synthesis of Small-Pore Chabazite Catalysts for NO x Abatement by Recycling Organic Structure-Directing Agents. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:655-665. [PMID: 36563090 DOI: 10.1021/acs.est.2c07239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The application of small-pore chabazite-type SSZ-13 zeolites, key materials for the reduction of nitrogen oxides (NOx) in automotive exhausts and the selective conversion of methane, is limited by the use of expensive N,N,N-trimethyl-1-ammonium adamantine hydroxide (TMAdaOH) as an organic structure-directing agent (OSDA) during hydrothermal synthesis. Here, we report an economical and sustainable route for SSZ-13 synthesis by recycling and reusing the OSDA-containing waste liquids. The TMAdaOH concentration in waste liquids, determined by a bromocresol green colorimetric method, was found to be a key factor for SSZ-13 crystallization. The SSZ-13 zeolite synthesized under optimized conditions demonstrates similar physicochemical properties (surface area, porosity, crystallinity, Si/Al ratio, etc.) as that of the conventional synthetic approach. We then used the waste liquid-derived SSZ-13 as the parent zeolite to synthesize Cu ion-exchanged SSZ-13 (i.e., Cu-SSZ-13) for ammonia-mediated selective catalytic reduction of NOx (NH3-SCR) and observed a higher activity as well as better hydrothermal stability than Cu-SSZ-13 by conventional synthesis. In situ infrared and ultraviolet-visible spectroscopy investigations revealed that the superior NH3-SCR performance of waste liquid-derived Cu-SSZ-13 results from a higher density of Cu2+ sites coordinated to paired Al centers on the zeolite framework. The technoeconomic analysis highlights that recycling OSDA-containing waste liquids could reduce the raw material cost of SSZ-13 synthesis by 49.4% (mainly because of the higher utilization efficiency of TMAdaOH) and, meanwhile, the discharging of wastewater by 45.7%.
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Affiliation(s)
- Wuwan Xiong
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Linhui Liu
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Anqi Guo
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Dongdong Chen
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Yulong Shan
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
| | - Mingli Fu
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Junliang Wu
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Daiqi Ye
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
| | - Peirong Chen
- National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, School of Environment and Energy, South China University of Technology, Guangzhou510006, China
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5
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Lin Q, Xu S, Zhao H, Liu S, Xu H, Dan Y, Chen Y. Highlights on Key Roles of Y on the Hydrothermal Stability at 900 °C of Cu/SSZ-39 for NH 3-SCR. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qingjin Lin
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu610064, China
- Research Institute of Natural Gas Technology, PetroChina Southwest Oil and Gasfield Company, Key Laboratory of Natural Gas Quality and Energy Measurement, CNPC, Chengdu610213, Sichuan, China
| | - Shuhao Xu
- Key Laboratory of Green Chemistry and Technology of Education Ministry, College of Chemistry, Sichuan University, Chengdu610064, China
| | - Hongyan Zhao
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu610064, China
| | - Shuang Liu
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu610064, China
| | - Haidi Xu
- Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu610064, China
- Sichuan Provincial Center of Engineering of Vehicular Exhaust Gases Abatement, Sichuan Provincial Center of Engineering of Environmental Catalytic Material, Chengdu610064, China
| | - Yi Dan
- State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu610064, China
| | - Yaoqiang Chen
- Key Laboratory of Green Chemistry and Technology of Education Ministry, College of Chemistry, Sichuan University, Chengdu610064, China
- Sichuan Provincial Center of Engineering of Vehicular Exhaust Gases Abatement, Sichuan Provincial Center of Engineering of Environmental Catalytic Material, Chengdu610064, China
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6
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Wu Y, Ma Y, Wang Y, Rappé KG, Washton NM, Wang Y, Walter ED, Gao F. Rate Controlling in Low-Temperature Standard NH 3-SCR: Implications from Operando EPR Spectroscopy and Reaction Kinetics. J Am Chem Soc 2022; 144:9734-9746. [PMID: 35605129 DOI: 10.1021/jacs.2c01933] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A series of seven Cu/SSZ-13 catalysts with Si/Al = 6.7 are used to elucidate key rate-controlling factors during low-temperature standard ammonia-selective catalytic reduction (NH3-SCR), via a combination of SCR kinetics and operando electron paramagnetic resonance (EPR) spectroscopy. Strong Cu-loading-dependent kinetics, with Cu atomic efficiency increasing nearly by an order of magnitude, is found when per chabazite cage occupancy for Cu ion increases from ∼0.04 to ∼0.3. This is due mainly to the release of intercage Cu transfer constraints that facilitates the redox chemistry, as evidenced from detailed Arrhenius analysis. Operando EPR spectroscopy studies reveal strong connectivity between Cu-ion dynamics and SCR kinetics, based on which it is concluded that under low-temperature steady-state SCR, kinetically most relevant Cu species are those with the highest intercage mobility. Transient binuclear Cu species are mechanistically relevant species, but their splitting and cohabitation are indispensable for low-temperature kinetics.
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Affiliation(s)
- Yiqing Wu
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Yue Ma
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Yilin Wang
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Kenneth G Rappé
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Nancy M Washton
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Yong Wang
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States.,Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99163, United States
| | - Eric D Walter
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
| | - Feng Gao
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, United States
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7
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Chen Z, Bian C, Guo Y, Pang L, Li T. Efficient Strategy to Regenerate Phosphorus-Poisoned Cu-SSZ-13 Catalysts for the NH 3-SCR of NO x: The Deactivation and Promotion Mechanism of Phosphorus. ACS Catal 2021. [DOI: 10.1021/acscatal.1c03752] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhen Chen
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Ce Bian
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Yanbing Guo
- College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Lei Pang
- DongFeng Trucks R&D Center, Zhushanhu Road No. 653, Wuhan 430056, P. R. China
| | - Tao Li
- Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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8
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Zhao H, Lin M, Wang Y, Zheng J. Effect of hydrothermal aging temperature on a Cu-SSZ-13/H-SAPO-34 composite for the selective catalytic reduction of NO x by NH 3. RSC Adv 2021; 11:33334-33343. [PMID: 35497511 PMCID: PMC9042250 DOI: 10.1039/d1ra05168g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/04/2021] [Indexed: 11/21/2022] Open
Abstract
Cu-SSZ-13 suffers activity loss after hydrothermal treatment at high temperatures, particularly above 850 °C. The stability of Cu-SSZ-13 can be enhanced by compositing with H-SAPO-34. This work investigates the effect of aging temperature on the composites. For the structure, the extra-framework P in H-SAPO-34 migrates and interacts with the Al in Cu-SSZ-13, forming a new framework P-Al bond. This interaction is enhanced with the increment of the aging temperature. For the cupric sites, the aging at 750 °C results in the agglomeration of Cu2+ ions to CuO. However, the sample aged at 800 °C exhibits higher activities than that aged at 750 °C, which might be attributed to the increased formation of framework P-Al bonds promoting the redispersion of CuO to Cu2+ ions. The composite suffers severe deactivation due to the significant loss of Cu2+ ions after aging at 850 °C.
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Affiliation(s)
- Huawang Zhao
- Department of Environmental Science & Engineering, College of Chemical Engineering, Huaqiao University Xiamen Fujian 361021 China
| | - Mimi Lin
- Xiamen Power Supply Company, State Grid Fujian Electric Power Co. Ltd. Xiamen Fujian 361001 China
| | - Yujie Wang
- School of Materials and Chemical Engineering, Chuzhou University Chuzhou Anhui 239000 China
| | - Jiandong Zheng
- School of Materials and Chemical Engineering, Chuzhou University Chuzhou Anhui 239000 China
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9
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Guo A, Xie K, Lei H, Rizzotto V, Chen L, Fu M, Chen P, Peng Y, Ye D, Simon U. Inhibition Effect of Phosphorus Poisoning on the Dynamics and Redox of Cu Active Sites in a Cu-SSZ-13 NH 3-SCR Catalyst for NO x Reduction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:12619-12629. [PMID: 34510889 DOI: 10.1021/acs.est.1c03630] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Phosphorus (P) stemming from biodiesel and/or lubricant oil additives is unavoidable in real diesel exhausts and deactivates gradually the Cu-SSZ-13 zeolite catalyst for ammonia-assisted selective catalytic NOx reduction (NH3-SCR). Here, the deactivation mechanism of Cu-SSZ-13 by P-poisoning was investigated by ex situ examination of the structural changes and by in situ probing the dynamics and redox of Cu active sites via a combination of impedance spectroscopy, diffuse reflection infrared Fourier transform spectroscopy, and ultraviolet-visible spectroscopy. We unveiled that strong interactions between Cu and P led to not only a loss of Cu active sites for catalytic turnovers but also a restricted dynamic motion of Cu species during low-temperature NH3-SCR catalysis. Furthermore, the CuII ↔ CuI redox cycling of Cu sites, especially the CuI → CuII reoxidation half-cycle, was significantly inhibited, which can be attributed to the restricted Cu motion by P-poisoning disabling the formation of key dimeric Cu intermediates. As a result, the NH3-SCR activity at low temperatures (200 °C and below) decreased slightly for the mildly poisoned Cu-SSZ-13 and considerably for the severely poisoned Cu-SSZ-13.
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Affiliation(s)
- Anqi Guo
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Kunpeng Xie
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Huarong Lei
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Valentina Rizzotto
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Limin Chen
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Mingli Fu
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Peirong Chen
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yue Peng
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Daiqi Ye
- Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ulrich Simon
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
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10
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Simancas R, Chokkalingam A, Elangovan SP, Liu Z, Sano T, Iyoki K, Wakihara T, Okubo T. Recent progress in the improvement of hydrothermal stability of zeolites. Chem Sci 2021; 12:7677-7695. [PMID: 34168820 PMCID: PMC8188473 DOI: 10.1039/d1sc01179k] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/27/2021] [Indexed: 01/14/2023] Open
Abstract
Zeolites have been successfully employed in many catalytic reactions of industrial relevance. The severe conditions required in some processes, where high temperatures are frequently combined with the presence of steam, highlight the need of considering the evolution of the catalyst structure during the reaction. This review attempts to summarize the recently developed strategies to improve the hydrothermal framework stability of zeolites.
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Affiliation(s)
- Raquel Simancas
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
| | - Anand Chokkalingam
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
| | - Shanmugam P Elangovan
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
| | - Zhendong Liu
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
- Institute of Engineering Innovation, The University of Tokyo 2-11-16 Yayoi, Bunkyo-ku Tokyo 113-8656 Japan
| | - Tsuneji Sano
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
| | - Kenta Iyoki
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
| | - Toru Wakihara
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
- Institute of Engineering Innovation, The University of Tokyo 2-11-16 Yayoi, Bunkyo-ku Tokyo 113-8656 Japan
| | - Tatsuya Okubo
- Department of Chemical System Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku Tokyo 13-8656 Japan
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