1
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Thermal ageing of a commercial LNT catalyst: Effects on the structure and functionalities. Catal Today 2022. [DOI: 10.1016/j.cattod.2021.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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2
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Measures to Reduce the N2O Formation at Perovskite-Based Lean NOx Trap Catalysts under Lean Conditions. Catalysts 2021. [DOI: 10.3390/catal11080917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The net oxidising atmosphere of lean burn engines requires a special after-treatment catalyst for NOx removal from the exhaust gas. Lean NOx traps (LNT) are such kind of catalysts. To increase the efficiency of LNTs at low temperatures platinised perovskite-based infiltration composites La0.5Sr0.5Fe1-xMxO3-δ/Al2O3 with M = Nb, Ti, Zr have been developed. In general, platinum based LNT catalysts show an undesired, hazardous formation of N2O in the lean operation mode due to a competing C3H6-selective catalytic reduction (SCR) at the platinum sites. To reduce N2O emissions an additional Rh-coating, obtained by incipient wetness impregnation, besides the Pt coating and a two-layered oxidation catalyst (2 wt.% Pd/20 wt.% CeO2/alumina)-LNT constitution, has been investigated. Though the combined Rh-Pt coating shows a slightly increased NOx storage capacity (NSC) at temperatures above 300 °C, it does not decrease N2O formation. The layered oxidation catalyst-LNT system shows a decrease in N2O formation of up to 60% at 200 °C, increasing the maximum NSC up to 176 µmol/g. Furthermore, the NSC temperature range is broadened compared to that of the pure LNT catalyst, now covering a range of 250–300 °C.
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3
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Schönebaum S, Dornseiffer J, Mauermann P, Wolkenar B, Sterlepper S, Wessel E, Iskandar R, Mayer J, Weirich TE, Pischinger S, Guillon O, Simon U. Composition/Performance Evaluation of Lean NO
x
Trap Catalysts for Coupling with SCR Technology. ChemCatChem 2021. [DOI: 10.1002/cctc.202001761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Simon Schönebaum
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute of Inorganic Chemistry (IAC) RWTH Aachen University Landoltweg 1 52074 Aachen Germany
| | - Jürgen Dornseiffer
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute of Energy and Climate Research: Materials Synthesis Processing (IEK-1) Forschungszentrum Jülich Leo-Brandt-Straße 52425 Jülich Germany
- JARA-ENERGY Wilhelm-Johnen-Straße 52425 Jülich Germany
| | - Peter Mauermann
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute for Combustion Engines Aachen (VKA) RWTH Aachen University Forckenbeckstraße 4 52074 Aachen Germany
| | - Bernd Wolkenar
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute for Combustion Engines Aachen (VKA) RWTH Aachen University Forckenbeckstraße 4 52074 Aachen Germany
| | - Stefan Sterlepper
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute for Combustion Engines Aachen (VKA) RWTH Aachen University Forckenbeckstraße 4 52074 Aachen Germany
| | - Egbert Wessel
- JARA-ENERGY Wilhelm-Johnen-Straße 52425 Jülich Germany
- Institute of Energy and Climate Research: Microstructure and Properties (IEK-2) Forschungszentrum Jülich Leo-Brandt-Straße 52425 Jülich Germany
| | - Riza Iskandar
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Central Facility for Electron Microscopy (GFE) RWTH Aachen University Ahornstraße 55 52074 Aachen Germany
| | - Joachim Mayer
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- JARA-ENERGY Wilhelm-Johnen-Straße 52425 Jülich Germany
- Central Facility for Electron Microscopy (GFE) RWTH Aachen University Ahornstraße 55 52074 Aachen Germany
| | - Thomas E. Weirich
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Central Facility for Electron Microscopy (GFE) RWTH Aachen University Ahornstraße 55 52074 Aachen Germany
| | - Stefan Pischinger
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- JARA-ENERGY Wilhelm-Johnen-Straße 52425 Jülich Germany
- Institute for Combustion Engines Aachen (VKA) RWTH Aachen University Forckenbeckstraße 4 52074 Aachen Germany
| | - Olivier Guillon
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute of Energy and Climate Research: Materials Synthesis Processing (IEK-1) Forschungszentrum Jülich Leo-Brandt-Straße 52425 Jülich Germany
- JARA-ENERGY Wilhelm-Johnen-Straße 52425 Jülich Germany
- Institute of Mineral Engineering (GHI) RWTH Aachen University Mauerstraße 5 52064 Aachen Germany
| | - Ulrich Simon
- Center for Automotive Catalytic Systems Aachen (ACA) RWTH Aachen University Schinkelstraße 8 52062 Aachen Germany
- Institute of Inorganic Chemistry (IAC) RWTH Aachen University Landoltweg 1 52074 Aachen Germany
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4
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Hybrid Technology for DeNOxing by LNT-SCR System for Efficient Diesel Emission Control: Influence of Operation Parameters in H2O + CO2 Atmosphere. Catalysts 2020. [DOI: 10.3390/catal10020228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The behavior and operation parameters were analyzed for the hybrid LNT-SCR (Lean NOx-Trap–Selective Catalytic Reduction) system with advanced catalyst formulations. Pt-Ba-K/Al2O3 was used as an NSR (NOx Storage and Reduction) or LNT catalyst effective in NOx and soot simultaneous removal whereas Cu-SAPO-34 with 2 wt.% of copper inside the structure was the small pore zeolite employed as the SCR catalyst. Under alternating and cyclic wet conditions, feeding volumetric concentrations of 1000 ppm of NO, 3% of O2, 1.5% of water, 0.3% of CO2, and H2 as a reductant, the NOx-conversion values were above 95% and a complete mineralization to nitrogen was registered using θ ≤ 3 (20 s of regeneration) and a hydrogen content between 10,000 and 2000 ppm in the whole temperature range tested. An excess of hydrogen fed (above 1% v/v) during the rich phase is unnecessary. In addition, in the low temperature range below 250 °C, the effect is more noticeable due to the further ammonia production and its possible slip. These results open the way to the scale up of the coupled catalytic technologies for its use in real conditions while controlling the influence of the operation map.
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5
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CO and hydrocarbon light-off inhibition by pre-adsorbed NOx on Pt/CeO2/Al2O3 and Pd/CeO2/Al2O3 diesel oxidation catalysts. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.115201] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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6
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Matarrese R, Castoldi L, Morandi S, Lietti L. Pathways for N2O Formation/Reduction During Operation of Commercial LNT Catalysts. Top Catal 2019. [DOI: 10.1007/s11244-018-1128-6] [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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7
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8
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Ting AWL, Harold MP, Balakotaiah V. Elucidating the mechanism of fast cycling NOx storage and reduction using C3H6 and H2 as reductants. Chem Eng Sci 2018. [DOI: 10.1016/j.ces.2018.05.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Castoldi L, Matarrese R, Liu C, Morandi S, Lietti L. Dynamics and Selectivity of N2O Formation/Reduction During Regeneration Phase of Pt-Based Catalysts. Top Catal 2018. [DOI: 10.1007/s11244-018-1022-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Balaji N, Aghalayam P, Kaisare NS. Global Kinetic Modeling and Analysis of Lean NO x Traps (LNT) Catalysts. Ind Eng Chem Res 2018. [DOI: 10.1021/acs.iecr.8b01435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nishithan Balaji
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Preeti Aghalayam
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
| | - Niket S. Kaisare
- Department of Chemical Engineering, Indian Institute of Technology Madras, Chennai 600036, India
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11
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Fast Cycling NOx Storage and Reduction: Identification of an Adsorbed Intermediate Pathway. Catal Letters 2018. [DOI: 10.1007/s10562-018-2405-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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13
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Granger P. Challenges and breakthroughs in post-combustion catalysis: how to match future stringent regulations. Catal Sci Technol 2017. [DOI: 10.1039/c7cy00983f] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This short overview briefly summarizes the prominent evolutions and scientific breakthroughs in the development of end-of-pipe technologies with respect to the standard regulations of atmospheric pollutant emissions from automotive exhaust.
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Affiliation(s)
- P. Granger
- Unité de Catalyse et de Chimie du Solide
- Université de Lille Sciences et Technologies
- France
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14
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Kubiak L, Righini L, Castoldi L, Matarrese R, Forzatti P, Lietti L, Daturi M. Mechanistic Aspects of N2O Formation Over Pt-Based Lean NOx Trap Catalysts. Top Catal 2016. [DOI: 10.1007/s11244-016-0577-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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15
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Prikhodko VY, Parks JE, Pihl JA, Toops TJ. Passive SCR for lean gasoline NOX control: Engine-based strategies to minimize fuel penalty associated with catalytic NH3 generation. Catal Today 2016. [DOI: 10.1016/j.cattod.2016.01.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Li M, Easterling VG, Harold MP. Spatio-temporal features of the sequential NOx storage and reduction and selective catalytic reduction reactor system. Catal Today 2016. [DOI: 10.1016/j.cattod.2016.01.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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18
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Morgan K, Touitou J, Choi JS, Coney C, Hardacre C, Pihl JA, Stere CE, Kim MY, Stewart C, Goguet A, Partridge WP. Evolution and Enabling Capabilities of Spatially Resolved Techniques for the Characterization of Heterogeneously Catalyzed Reactions. ACS Catal 2016. [DOI: 10.1021/acscatal.5b02602] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin Morgan
- School
of Mechanical and Aerospace Engineering, Queen’s University Belfast, Ashby Building, Stranmillis Road, Belfast BT9 5AH, United Kingdom
| | - Jamal Touitou
- Department
of Chemical and Materials Engineering, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jae-Soon Choi
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Ciarán Coney
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Christopher Hardacre
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Josh A. Pihl
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Cristina E. Stere
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Mi-Young Kim
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
| | - Caomhán Stewart
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Alexandre Goguet
- School
of Chemistry and Chemical Engineering, Queen’s University Belfast, David
Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - William P. Partridge
- Fuels,
Engines and Emissions Research Center, Oak Ridge National Laboratory, P.O. Box 2008,
MS-6472, Oak Ridge, Tennessee 37831-6472, United States
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19
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Jabłońska M, Palkovits R. It is no laughing matter: nitrous oxide formation in diesel engines and advances in its abatement over rhodium-based catalysts. Catal Sci Technol 2016. [DOI: 10.1039/c6cy01126h] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
N2O appears as one of the undesired by-products in exhaust gases emitted from diesel engine aftertreatment systems, such as diesel oxidation catalysts (DOC), lean NOx trap (LNT, also known as NOx storage and reduction (NSR)) or selective catalytic reduction (NH3-SCR and HC-SCR) and ammonia slip catalysts (ASC, AMOX, guard catalyst).
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Affiliation(s)
- Magdalena Jabłońska
- Chair of Heterogeneous Catalysis and Chemical Technology
- Institut für Technische und Makromolekulare Chemie
- RWTH Aachen University
- 52074 Aachen
- Germany
| | - Regina Palkovits
- Chair of Heterogeneous Catalysis and Chemical Technology
- Institut für Technische und Makromolekulare Chemie
- RWTH Aachen University
- 52074 Aachen
- Germany
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20
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Wang J, Wang X, Zhu J, Wang J, Shen M. Elucidating N2O Formation during the Cyclic NOx Storage and Reduction Process Using CO as a Reductant. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:7965-7973. [PMID: 26024310 DOI: 10.1021/acs.est.5b00712] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The N2O formation pathway and effect of H2O on N2O formation during the NOx storage and reduction (NSR) process using CO as a reductant were investigated over a Pt-BaO/Al2O3 catalyst. The NSR activity measurements and transient in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments were performed to evaluate N2O evolution and elucidate the N2O formation mechanism. N2O is formed in the lean, rich, and delay2 phases. In the lean phase, N2O formation is related to the reactions between surface isocyanate and gaseous NO/O2 and NO is more responsible for N2O formation than O2. Moreover, N2O production decreases with H2O because of the hydrolysis of isocyanate species. In the rich phase, the amount of N2O formation also decreases in the presence of H2O at a higher temperature because of the high reduction ability of H2 generated from the water-gas shift (WGS) reaction. During the delay2 phase, N2O is mainly formed by nitrite species reacting with Pt(0)-CO. Furthermore, the presence of H2O decreases the stability of nitrites and results in more N2O production at a low temperature.
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Affiliation(s)
| | | | | | | | - Meiqing Shen
- ‡Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People's Republic of China
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21
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Zhu J, Wang J, Wang J, Lv L, Wang X, Shen M. New Insights into the N2O formation mechanism over Pt-BaO/Al2O3 model catalysts using H2 as a reductant. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:504-512. [PMID: 25495837 DOI: 10.1021/es5046106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The N2O formation mechanism was investigated over a Pt-BaO/Al2O3 catalyst applied on light-duty diesel vehicles using H2 as a reductant in the absence and presence of H2O. In the absence of H2O, N2O forms mainly at the initial phase of lean NOx trapping; while in the presence of H2O, N2O appears mainly at the beginning of the rich reduction phase. In the lean period, N2O is formed via the gaseous NO/O2 reacting with the adsorbed H and NH3 that are formed during the previous rich period. The N2O formation in the rich period is insignificant in the absence of H2O but is greatly enhanced by the presence of H2O. The amount of N2O formed is proportional to the H2O level in the feed, and its formation is favored at low temperatures. Our FTIR data show that H2O enhances the rate of nitrite/nitrate reduction during the rich regeneration, which increases the amount of released NOx, an oxygen source for N2O formation. Our temperature-programmed experiments indicate that H2O competes with NH3 for adsorption sites on Pt surface. This competitive adsorption may increase the NH3 desorption rate at low temperatures in the rich phase and make Pt surface more accessible to NO.
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Affiliation(s)
- Jinxin Zhu
- Key Laboratory for Green Chemical Technology of State Education Ministry, School of Chemical Engineering & Technology, Tianjin University , Tianjin 300072, PR China
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22
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Origin of double dinitrogen release feature during fast switching between lean and rich cycles for NO storage reduction catalysts. J Catal 2014. [DOI: 10.1016/j.jcat.2014.05.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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