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Analysis and Modeling of NOx Reduction Based on the Reactivity of Cu Active Sites and Brønsted Acid Sites in a Cu-Chabazite SCR Catalyst
Technical Paper
2019-24-0150
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
The NOx-reducing activity of a Cu-chabazite selective catalytic reduction (SCR) catalyst was analyzed over a wide temperature range. The analysis was based on the ammonia SCR (NH3-SCR) mechanism and accounted for Cu redox chemistry and reactions at Brønsted acid sites. The reduction of NOx to N2 (De-NOx) at Cu sites was found to proceed via different paths at low and high temperatures. Consequently, the rate-limiting step of the SCR reaction at Cu sites varied with the temperature. The rate of NOx reduction at Cu sites below 200°C was determined by the rate of Cu oxidation. Conversely, the rate of NOx reduction above 300°C was determined by the rate of NH3 adsorption on Cu sites. Moreover, the redox state of the active Cu sites differed at low and high temperatures. To clarify the role of the chabazite Brønsted acid sites, experiments were also performed using a H-chabazite catalyst that lacks Cu sites. NOx reduction via the NO2-NH3 reaction was found to occur at Brønsted acid sites at high temperatures (up to 600°C). We also analyzed the chabazite catalyst’s activity towards NH3 oxidation, which significantly affects NOx reduction at high temperatures. Cu sites were required for NH3 oxidation; NH3 was not oxidized in their absence. However, the formation of the by-product NO increased as the content of Brønsted acid sites in the Cu-chabazite catalyst decreased. It was therefore suggested that Brønsted acid sites contribute to the reduction of NO formed during NH3 oxidation. Numerical studies were conducted to develop an SCR reaction model that incorporates these processes. The resulting model accurately predicted the outcomes of NOx reduction experiments under diverse conditions including some involving transient temperature changes.
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Tsukamoto, Y., Fukuma, T., and Kusaka, J., "Analysis and Modeling of NOx Reduction Based on the Reactivity of Cu Active Sites and Brønsted Acid Sites in a Cu-Chabazite SCR Catalyst," SAE Technical Paper 2019-24-0150, 2019, https://doi.org/10.4271/2019-24-0150.Data Sets - Support Documents
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References
- Paolucci , C. , Verma , A.A. , Bates , S.A. , Kispersky , V.F. et al. Isolation of the Copper Redox Steps in the Standard Selective Catalytic Reduction on Cu-SSZ-13 Angew. Chem. Int. Ed. 53 11828 11833 2014 10.1002/anie.201407030
- Janssens , T.V.W. , Falsig , H. , Lundegaard , L.F. , Vennestrøm , P.N.R. et al. A Consistent Reaction Scheme for the Selective Catalytic Reduction of Nitrogen Oxides with Ammonia ACS Catal. 5 2832 −2845 2015 10.1021/cs501673g
- Tsukamoto , Y. , Utaki , S. , Fukuma , T. , and Kusaka , J. Reactivity Analysis and Modeling of Cu-SCR Based on NH 3 -SCR Mechanism Considering Cu Redox JSAE 6 1211 1216 2018 10.11351/jsaeronbun.49.1211
- Lezcano-Gonzalez , I. , Deka , U. , Arstad , B. , Van Yperen-De Deyne , A. et al. Determining the Storage, Availability and Reactivity of NH 3 within Cu-Chabazite-based Ammonia Selective Catalytic Reduction Systems Phys. Chem. Chem. Phys. 16 1639 1650 2014 10.1039/c3cp54132k
- Zhu , H. , Kwak , J.H. , Peden , C.H.F. , and Szanyi , J. In Situ DRIFTS-MS Studies on the Oxidation of Adsorbed NH 3 by NOx over a Cu-SSZ-13 Zeolite Catalysis Today 205 16 23 2013 10.1016/j.cattod.2012.08.043
- Ohya , N. , Hiyama , K. , Tanaka , K. , Konno , M. et al. Kinetic Modeling Study of NOx Conversion Based on Physicochemical Characteristics of Hydrothermally Aged SCR/DPF Catalyst SAE Int. J. Fuels Lubr. 10 3 2017 10.4271/2017-01-2386
- Gao , F. , Walter , E.D. , Karp , E.M. , Luo , J. et al. Structure-Activity Relationships in NH 3 -SCR Over Cu-SSZ-13 as Probed by Reaction Kinetics and EPR Studies Journal of Catalysis 300 20 29 2013 10.1016/j.jcat.2012.12.020
- Olsson , L. , Sjövall , H. , and Blint , R.J. A Kinetic Model for Ammonia Selective Catalytic Reduction Over Cu-ZSM-5 Applied Catalysis B: Environmental 81 3-4 203 217 2008 10.1016/j.apcatb.2007.12.011
- Sjövall , H. , Blint , R.J. , and Olsson , L. Detailed Kinetic Modeling of NH 3 and H 2 O Adsorption, and NH 3 Oxidation over Cu-ZSM-5 J. Phys. Chem. C 113 4 1393 1405 2009 10.1021/jp802449s
- Colombo , M. , Nova , I. , and Tronconi , E. Detailed Kinetic Modeling of the NH 3 -NO/NO 2 SCR Reactions Over a Commercial Cu-zeolite Catalyst for Diesel Exhausts After Treatment Catalysis Today 197 243 255 2012 10.1016/j.cattod.2012.09.002
- Su , C. , Brault , J. , Munnannur , A. , Liu , Z. et al. Model-Based Approaches in Developing an Advanced Aftertreatment System: An Overview SAE Technical Paper 2019-01-0026 2019 10.4271/2019-01-0026
- Colombo , M. , Koltsakis , G. , Nova , I. , and Tronconi , E. Modelling the Ammonia Adsorption-Desorption Process over an Fe-Zeolite Catalyst for SCR Automotive Applications Catalysis Today 188 1 42 52 July 1, 2012 10.1016/j.cattod.2011.09.002
- Olsson , L. , Wijayanti , K. , Leistner , K. , Kumar , A. et al. A Multi-Site Kinetic Model for NH 3 -SCR Over Cu/SSZ-13 Applied Catalysis B: Environmental 174-175 212 224 2015 10.1016/j.apcatb.2015.02.037
- Bendrich , M. , Scheuer , A. , Hayes , R.E. , and Votsmeier , M. Unified Mechanistic Model for Standard SCR, Fast SCR, and NO 2 SCR Over a Copper Chabazite Catalyst Applied Catalysis B: Environmental 222 76 87 March 2018 10.1016/j.apcatb.2017.09.069 axisuite documentation version 2017A
- Paolucci , C. , Parekh , A.A. , Khurana , I. , Di Iorio , J.R. et al. Catalysis in a Cage: Condition-Dependent Speciation and Dynamics of Exchanged Cu Cations in SSZ-13 Zeolites J. Am. Chem. Soc. 138 6028 6048 2016 10.1021/jacs.6b02651
- Gao , F. , Mei , D. , Wang , Y. , Szanyi , J. , and Peden , C.H.F. Selective Catalytic Reduction over Cu/SSZ-13: Linking Homo- and Heterogeneous Catalysis J. Am. Chem. Soc. 139 4935 4942 2017 10.1021/jacs.7b01128
- Jabłon´ska , M. and Palkovits , R. Copper Based Catalysts for the Selective Ammonia Oxidation into Nitrogen and Water Vapour - Recent Trends and Open Challenges Applied Catalysis B: Environmental 181 332 351 2016 10.1016/j.apcatb.2015.07.017
- Magdalena , J.A.B.Ł.O.Ń.S.K.A. , Lucjan , C.H.M.I.E.L.A.R.Z. , and Agnieszka , W.Ę.G.R.Z.Y.N. Selective Catalytic Oxidation (SCO) of Ammonia into Nitrogen and Water Vapour over Hydrotalcite Originated Mixed Metal Oxides - a Short Review CHEMIK 2013 67 8 701 710 10.1007/s10562-011-0653-8
- Hinokuma , S. , Matsuki , S. , Kawabata , Y. , Shimanoe , H. et al. Copper Oxides Supported on Aluminum Oxide Borates for Catalytic Ammonia Combustion J. Phys. Chem. C 120 24734 24742 2016 10.1021/acs.jpcc.6b07157
- Smith , M.A. , Depcik , C.D. , Klinkert , S. , Hoard , J.W. , Bohac , S.V. , and Assanis , D.N. NO 2 Reaction Pathways With NH 3 on an Fe-Zeolite SCR Catalyst ASME 2011 Internal Combustion Engine Division Fall Technical Conference 633 641 10.1115/ICEF2011-60114
- Gao , F. , Walter , E.D. , Kollar , M. , Wang , Y. et al. Understanding Ammonia Selective Catalytic Reduction Kinetics over Cu/SSZ-13 from Motion of the Cu Ions Journal of Catalysis 319 1 14 2014 10.1016/j.jcat.2014.08.010
- Gao , F. , Washton , N.M. , Wang , Y. , Kollár , M. et al. Effects of Si/Al Ratio on Cu/SSZ-13 NH3-SCR Catalysts: Implications for the Active Cu Species and the Roles of Brønsted Acidity Journal of Catalysis 331 25 38 2015 10.1016/j.jcat.2015.08.004
- Li , H. , Paolucci , C. , Khurana , I. , Wilcox , L.N. et al. Consequences of Exchange-Site Heterogeneity and Dynamics on the UV-Visible Spectrum of Cu-Exchanged SSZ-13 Chem. Sci. 10 2373 2019 10.1039/c8sc05056b
- Auvray , X. , Partridge , W. , Choi , J.-S. , Pihl , J. et al. Kinetic Modeling of NH 3 -SCR over a Supported Cu Zeolite Catalystusing Axial Species Distribution Measurements Applied Catalysis B: Environmental 163 393 403 2015 10.1016/j.apcatb.2014.08.003
- Vollmer , J.M. , Stefanovich , E.V. , and Truong , T.N. Molecular Modeling of Interactions in Zeolites: An Ab Initio Embedded Cluster Study of NH 3 Adsorption in Chabazite J. Phys. Chem. B 103 9415 9422 1999 10.1021/jp990571h