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Lyu Y, Lyu G, Dong X, Song C. Characterization of the H 2/NOx reaction process over the La 0.9Ce 0.1Co 0.9Pd 0.1O 3-BaO/Al 2O 3 catalyst. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134184. [PMID: 38569344 DOI: 10.1016/j.jhazmat.2024.134184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/29/2024] [Accepted: 03/30/2024] [Indexed: 04/05/2024]
Abstract
An excellent textual properties and performance La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst was synthesized. The reaction mechanism of H2/NOx over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst was investigated by temperature programmed reduction/ desorption/ surface reaction (TPR/D/SR) technologies and in-situ diffuse reflectance Fourier transform (DRIFT) technology. The results show that cerium or palladium species are inserted into the cells of LaCoO3, as well as they synergetic promote the redox properties of the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst. Surface activated nitrates exist over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst, with thermal stable increasing in the order: absorbed N2O4 < monodentate nitrates < chelating bidentate nitrates < nitrates unidentate < free ionic nitrates < bulk free ionic nitrates. H2 preferentially reacted with absorbed N2O4 and monodentate nitrates at low temperatures, due to their high activity. The concentration of generated NH3 from the redox reaction of H2/NOx achieves the maximum value between 350 and 450 °C over the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst. Compared with the NOx adsorption process at 50 °C, monodentate nitrates and absorbed N2O4 disappeared due to their low thermal stability, chelating bidentate nitrates become stronger, as well as free ionic nitrates converted to bulk free ionic nitrates with higher thermal stability at 350 °C. When H2 is exposed to NOx species adsorbed on La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3, chelating bidentate nitrates and bulk free ionic nitrates are consumed gradually, indicating that although the bulk free ionic nitrates own high stability, it also could be consumed by involving in the H2/NOx reaction at 350 °C. The quantitative H2/NO reaction experiments confirmed the results of H2-TPSR and NSR. It is beneficial to the formation of NH3 when the H2/NO ratio is more than 2.5. Comparing traditional Pt-BaO/Al2O3 catalyst, the La0.9Ce0.1Co0.9Pd0.1O3-BaO/Al2O3 catalyst exhibit an excellent performance, including considerable NH3 production property, lower N2O selectivity, and the precious metal saving.
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Affiliation(s)
- Yu Lyu
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Gang Lyu
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Xiangyu Dong
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China
| | - Chonglin Song
- State Key Laboratory of Engines, Tianjin University, Tianjin 300072, China.
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Jawhari AH, Hasan N, Radini IA, Narasimharao K, Malik MA. Noble Metals Deposited LaMnO 3 Nanocomposites for Photocatalytic H 2 Production. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12172985. [PMID: 36080023 PMCID: PMC9458141 DOI: 10.3390/nano12172985] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/21/2022] [Accepted: 08/23/2022] [Indexed: 06/01/2023]
Abstract
Due to the growing demand for hydrogen, the photocatalytic hydrogen production from alcohols present an intriguing prospect as a potential source of low-cost renewable energy. The noble metals (Ag, Au, Pd and Pt) deposited LaMnO3 nanocomposites were synthesized by a non-conventional green bio-reduction method using aqueous lemon peel extract, which acts as both reducing and capping agent. The successful deposition of the noble metals on the surface of LaMnO3 was verified by using powder XRD, FTIR, TEM, N2-physisorption, DR UV-vis spectroscopy, and XPS techniques. The photocatalytic activity of the synthesized nanocomposites was tested for photocatalytic H2 production under visible light irradiation. Different photocatalytic reaction parameters such as reaction time, pH, catalyst mass and reaction temperature were investigated to optimize the reaction conditions for synthesized nanocomposites. Among the synthesized noble metal deposited LaMnO3 nanocomposites, the Pt-LaMnO3 nanocomposite offered superior activity for H2 production. The enhanced photocatalytic activity of the Pt-LaMnO3 was found as a result from low bandgap energy, high photoelectrons generation and enhanced charge separation due to deposition of Pt nanoparticles. The effective noble metal deposition delivers a new route for the development of plasmonic noble metal-LaMnO3 nanocomposites for photocatalytic reforming of aqueous methanol to hydrogen.
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Affiliation(s)
- Ahmed Hussain Jawhari
- Department of Chemistry, Faculty of Science, Jazan University, Jazan 45142, Saudi Arabia
| | - Nazim Hasan
- Department of Chemistry, Faculty of Science, Jazan University, Jazan 45142, Saudi Arabia
| | - Ibrahim Ali Radini
- Department of Chemistry, Faculty of Science, Jazan University, Jazan 45142, Saudi Arabia
| | | | - Maqsood Ahmad Malik
- Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
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Study of Ce, Ca, Fe, and Mn-Doped LaCoO 3 Perovskite Oxide for the Four-Way Purification of PM, NO x, CO, and HC from Diesel Engine Exhaust. MATERIALS 2022; 15:ma15124149. [PMID: 35744208 PMCID: PMC9228900 DOI: 10.3390/ma15124149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 11/27/2022]
Abstract
Perovskite-type catalysts were widely used in the field of automobile exhaust purification due to their inherent physicochemical properties and excellent doping characteristics. A series of La1−xMxCo1−yNyO3 (M = Ce, Ca; N = Fe, Mn) perovskite-type catalyst samples were prepared by sol-gel method for the four-way purification of PM, NOx, CO, and HC emitted by diesel exhaust. The activity of catalyst samples was tested by simulation experiments and hydrogen temperature-programmed reduction (H2-TPR). Catalyst samples were characterized by means of XRD, FT-IR, SEM, BET, and XPS analysis. The results demonstrated that the perovskite-type catalyst samples with a particle pore size of 3–5 μm can be prepared by sol-gel method. When A-site of LaCoO3 perovskite-type oxide was doped by cerium ions, the catalyst samples produced small distortion. The doping of cerium ions to A-site was more conducive to the four-way purification of diesel exhaust than calcium ions. La0.8Ce0.2CoO3 perovskite-type samples showed the best purification efficiency, and the purification efficiencies of PM, NOx, CO, and HC were 90%, 85%, 94%, and 100%, respectively. When the B-site of La0.8Ce0.2CoO3 perovskite was doped with iron ions, the purification efficiency of catalyst samples for PM and NOx can be further enhanced. When the B-site of La0.8Ce0.2CoO3 perovskite was doped with manganese ions, the purification efficiency of the catalyst samples for PM can be further enhanced. It can be seen from the simulation experiments that La0.8Ce0.2Co0.7Fe0.3O3 perovskite was the best doping amount, and the purification efficiencies of PM, NOx, CO, and HC were 95%, 92%, 94%, and 100%, respectively.
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Zhao D, Yang Y, Gao Z, Tian Y, Zhang J, Jiang Z, Li X. A-site defects in LaSrMnO3 perovskite-based catalyst promoting NO storage and reduction for lean-burn exhausts. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2020.04.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Perovskite-Based Catalysts as Efficient, Durable, and Economical NOx Storage and Reduction Systems. Catalysts 2020. [DOI: 10.3390/catal10020208] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Diesel engines operate under net oxidizing environment favoring lower fuel consumption and CO2 emissions than stoichiometric gasoline engines. However, NOx reduction and soot removal is still a technological challenge under such oxygen-rich conditions. Currently, NOx storage and reduction (NSR), also known as lean NOx trap (LNT), selective catalytic reduction (SCR), and hybrid NSR–SCR technologies are considered the most efficient control after treatment systems to remove NOx emission in diesel engines. However, NSR formulation requires high platinum group metals (PGMs) loads to achieve high NOx removal efficiency. This requisite increases the cost and reduces the hydrothermal stability of the catalyst. Recently, perovskites-type oxides (ABO3) have gained special attention as an efficient, economical, and thermally more stable alternative to PGM-based formulations in heterogeneous catalysis. Herein, this paper overviews the potential of perovskite-based formulations to reduce NOx from diesel engine exhaust gases throughout single-NSR and combined NSR–SCR technologies. In detail, the effect of the synthesis method and chemical composition over NO-to-NO2 conversion, NOx storage capacity, and NOx reduction efficiency is addressed. Furthermore, the NOx removal efficiency of optimal developed formulations is compared with respect to the current NSR model catalyst (1–1.5 wt % Pt–10–15 wt % BaO/Al2O3) in the absence and presence of SO2 and H2O in the feed stream, as occurs in the real automotive application. Main conclusions are finally summarized and future challenges highlighted.
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Jabłońska M, Palkovits R. Perovskite-based catalysts for the control of nitrogen oxide emissions from diesel engines. Catal Sci Technol 2019. [DOI: 10.1039/c8cy02458h] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nitrogen oxides removal over a wide range of perovskite-based catalysts together with their property-activity relationships.
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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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Li T, Sun W, Zhou Z, Xie T, Cao L, Yang J. Di-metal-doped sulfur resisting perovskite catalysts for highly efficient H 2-SCR of NO. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:25504-25514. [PMID: 29956259 DOI: 10.1007/s11356-018-2608-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 06/18/2018] [Indexed: 06/08/2023]
Abstract
Lanthanide perovskite catalysts doped with limited palladium (to improve activity) and cerium (to improve sulfur resistance) were prepared using sol-gel method. In different B sites, lanthanide perovskites were studied at harsh conditions for H2 selective catalytic reduction of NO. The activity sequence was as follows: LaCeMnPd > LaCeCoPd > LaCeFePd. LaCeMnPd had a high NO conversion of 96.6% at only 150 °C. And it also had a surprising SO2 resistance in different SO2 concentrations. After cutting out SO2, NO conversion recovered rapidly to its original level, indicating that the slight deactivation was reversible. In addition, the effect of gas hourly space velocity, H2/NO ratio, O2, and SO2 concentration was studied. And XRD, energy-dispersive X-ray, SEM, XPS, H2-temperature programmed reduction, and NH3-temperature programmed desorption were performed to characterize the catalysts. Graphical abstract ᅟ.
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Affiliation(s)
- Tingting Li
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Wei Sun
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Zhenhua Zhou
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Tianying Xie
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Limei Cao
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China
| | - Ji Yang
- School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
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Liang X, Wu C, Yu X, Huang W, Yin H. Pd Doped La0.1Sr0.9TiO3 as High-Temperature Water-Gas Shift Catalysts: In-Situ Formation of Active Pd Phase. Catal Letters 2018. [DOI: 10.1007/s10562-018-2462-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Teng Z, Zhang H, Huang S, Li N, Zhou Q. Experimental study on reduction of NO by CH 4 over La 0.8 Sr 0.2 MnO 3 /α-Al 2 O 3 in excess of O 2. J Taiwan Inst Chem Eng 2018. [DOI: 10.1016/j.jtice.2018.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Catalytic Oxidation of Soot on a Novel Active Ca-Co Dually-Doped Lanthanum Tin Pyrochlore Oxide. MATERIALS 2018; 11:ma11050653. [PMID: 29695051 PMCID: PMC5978030 DOI: 10.3390/ma11050653] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/03/2018] [Accepted: 04/19/2018] [Indexed: 12/04/2022]
Abstract
A novel active Ca-Co dually-doping pyrochlore oxide La2−xCaxSn2−yCoyO7 catalyst was synthesized by the sol-gel method for catalytic oxidation of soot particulates. The microstructure, atomic valence, reduction, and adsorption performance were investigated by X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), H2-TPR (temperature-programmed reduction), and in situ diffuse reflection infrared Fourier transformed (DRIFTS) techniques. Temperature programmed oxidation (TPO) tests were performed with the mixture of soot-catalyst under tight contact conditions to evaluate the catalytic activity for soot combustion. Synergetic effect between Ca and Co improved the structure and redox properties of the solids, increased the surface oxygen vacancies, and provided a suitable electropositivity for oxide, directly resulting in the decreased ignition temperature for catalyzed soot oxidation as low as 317 °C. The presence of NO in O2 further promoted soot oxidation over the catalysts with the ignition temperature decreased to about 300 °C. The DRIFTS results reveal that decomposition of less stable surface nitrites may account for NO2 formation in the ignition period of soot combustion, which thus participate in the auxiliary combustion process.
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Royer S, Duprez D, Can F, Courtois X, Batiot-Dupeyrat C, Laassiri S, Alamdari H. Perovskites as substitutes of noble metals for heterogeneous catalysis: dream or reality. Chem Rev 2014; 114:10292-368. [PMID: 25253387 DOI: 10.1021/cr500032a] [Citation(s) in RCA: 358] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sébastien Royer
- Université de Poitiers , CNRS UMR 7285, IC2MP, 4 Rue Michel Brunet, TSA 51106, 86073 Poitiers Cedex, France
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Abstract
AbstractThe most relevant information about the different active phases that have been studied for the catalytic combustion of soot is reviewed and discussed in this article. Many catalysts have been reported to accelerate soot combustion, including formulations with noble metals, alkaline metals and alkaline earth metals, transition metals that can accomplish redox cycles (V, Mn, Co, Cu, Fe, etc.), and internal transition metals. Platinum catalysts are among those of most interest for practical applications, and an important feature of these catalysts is that sulphur-resistant platinum formulations have been prepared. Some metal oxide-based catalysts also appear to be promising candidates for soot combustion in practical applications, including ceria-based formulations and mixed oxides with perovskite and spinel structures. Some of these metal oxide catalysts produce highly reactive active oxygen species that promote efficient soot combustion. Thermal stability is an important requirement for a soot combustion catalyst, which precludes the practical utilisation of several potential catalysts such as most alkaline metal catalysts, molten salts, and metal chlorides. Some noble metal catalysts are also unstable due to the formation of volatile oxides (ruthenium, iridium, and osmium).
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LIU S, CONG Y, KAPPENSTEIN C, ZHANG T. Effect of Zirconium in La(Ba)ZrxCo1-xO3-δ Perovskite Catalysts for N2O Decomposition. CHINESE JOURNAL OF CATALYSIS 2012. [DOI: 10.1016/s1872-2067(11)60402-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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