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Chen PW, Maiti D, Liu RF, Grabow LC, Harold MP. Tailored Platinum Group Metal/Spinel Oxide Catalysts for Dynamically Enhanced Methane Oxidation. ACS ENGINEERING AU 2024; 4:193-203. [PMID: 38646517 PMCID: PMC11027098 DOI: 10.1021/acsengineeringau.3c00053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 04/23/2024]
Abstract
A combined experimental and molecular modeling study identifies a family of spinel oxides that in combination with PGM (platinum group metals) provide enhanced methane oxidation activity. With a reduction in greenhouse gas (GHG) emissions urgently needed, there is renewed interest in the use of natural gas vehicles (NGVs) and engines (NGEs) for transportation, commerce, and industrial applications. NGVs and NGEs emit less CO2 than their petroleum-derived counterparts but may emit uncombusted methane, an even more potent GHG. For stoichiometric engines, methane oxidation catalysts containing PGM and spinel oxide in layered architectures offer increased methane oxidation activity and lower light-off temperatures (T50). The reducible spinel oxide has direct and indirect roles that are effectively described by the bulk oxygen vacancy formation energy (Evac). We apply density functional theory (DFT) to identify several earth-abundant, cobalt-rich spinel oxides with favorable Evac, shown to correlate with dynamic oxygen storage capacity (DOSC) and CO and H2 oxidation activity. We experimentally rank-order the DFT-identified spinel oxides in combination with Pt+Pd for their methane oxidation activity measurements, under both time-invariant and modulated feed conditions. We show good agreement between the activity and the DFT-computed reducibility of the spinel oxide. The findings suggest spinel reducibility is a key factor in achieving enhanced low-temperature methane conversion, enabled through a balance of methane activation on the PGM sites and subsequent oxidation of the intermediates and byproducts on spinel oxides. In agreement with its computationally predicted Evac, NiCo2O4 was confirmed to have the highest DOSC and lowest T50 among the tested spinel samples.
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Affiliation(s)
- Pak Wing Chen
- William
A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
| | - Debtanu Maiti
- William
A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
| | - Ru-Fen Liu
- CDTi
Advanced Materials, Inc., 1641 Fiske Place, Oxnard, California 93033, United States
| | - Lars C. Grabow
- William
A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
- Texas
Center for Superconductivity at the University of Houston (TcSUH), Houston, Texas 77204, United States
| | - Michael P. Harold
- William
A Brookshire Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
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Soto Beobide A, Moschovi AM, Mathioudakis GN, Kourtelesis M, Lada ZG, Andrikopoulos KS, Sygellou L, Dracopoulos V, Yakoumis I, Voyiatzis GA. High Catalytic Efficiency of a Nanosized Copper-Based Catalyst for Automotives: A Physicochemical Characterization. Molecules 2022; 27:7402. [PMID: 36364229 PMCID: PMC9657973 DOI: 10.3390/molecules27217402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/21/2022] [Accepted: 10/26/2022] [Indexed: 06/26/2024] Open
Abstract
The global trend in restrictions on pollutant emissions requires the use of catalytic converters in the automotive industry. Noble metals belonging to the platinum group metals (PGMs, platinum, palladium, and rhodium) are currently used for autocatalysts. However, recent efforts focus on the development of new catalytic converters that combine high activity and reduced cost, attracting the interest of the automotive industry. Among them, the partial substitution of PGMs by abundant non-PGMs (transition metals such as copper) seems to be a promising alternative. The PROMETHEUS catalyst (PROM100) is a polymetallic nanosized copper-based catalyst for automotives prepared by a wet impregnation method, using as a carrier an inorganic mixed oxide (CeO2-ZrO2) exhibiting elevated oxygen storage capacity. On the other hand, catalyst deactivation or ageing is defined as the process in which the structure and state of the catalyst change, leading to the loss of the catalyst's active sites with a subsequent decrease in the catalyst's performance, significantly affecting the emissions of the catalyst. The main scope of this research is to investigate in detail the effect of ageing on this low-cost, effective catalyst. To that end, a detailed characterization has been performed with a train of methods, such as SEM, Raman, XRD, XRF, BET and XPS, to both ceria-zirconia mixed inorganic oxide support (CZ-fresh and -aged) and to the copper-based catalyst (PROM100-fresh and -aged), revealing the impact of ageing on catalytic efficiency. It was found that ageing affects the Ce-Zr mixed oxide structure by initiating the formation of distinct ZrO2 and CeO2 structures monitored by Raman and XRD. In addition, it crucially affects the morphology of the sample by reducing the surface area by a factor of nearly two orders of magnitude and increasing particle size as indicated by BET and SEM due to sintering. Finally, the Pd concentration was found to be considerably reduced from the material's surface as suggested by XPS data. The above-mentioned alterations observed after ageing increased the light-off temperatures by more than 175 °C, compared to the fresh sample, without affecting the overall efficiency of the catalyst for CO and CH4 oxidation reactions. Metal particle and CeZr carrier sintering, washcoat loss as well as partial metal encapsulation by Cu and/or CeZrO4 are identified as the main causes for the deactivation after hydrothermal ageing.
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Affiliation(s)
- Amaia Soto Beobide
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
| | | | - Georgios N. Mathioudakis
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
| | | | - Zoi G. Lada
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
| | - Konstantinos S. Andrikopoulos
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
- Department of Physics, University of Patras, 26504 Patras, Greece
| | - Labrini Sygellou
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
| | - Vassilios Dracopoulos
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
| | | | - George A. Voyiatzis
- Foundation for Research and Technology, Institute of Chemical Engineering Sciences FORTH/ICE-HT, 26504 Patras, Greece
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Kreitz B, Lott P, Bae J, Blöndal K, Angeli S, Ulissi ZW, Studt F, Goldsmith CF, Deutschmann O. Detailed Microkinetics for the Oxidation of Exhaust Gas Emissions through Automated Mechanism Generation. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bjarne Kreitz
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Patrick Lott
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Jongyoon Bae
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Katrín Blöndal
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Sofia Angeli
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
| | - Zachary W. Ulissi
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Felix Studt
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
- Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - C. Franklin Goldsmith
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
| | - Olaf Deutschmann
- Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany
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Walter R, Neumann J, Hinrichsen O. Modeling the Catalytic Performance of Coated Gasoline Particulate Filters under Various Operating Conditions. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03631] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Raimund Walter
- BMW Group, Development Powertrain, Schleißheimer 422, D-80937 Munich, Germany
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, D-85748 Garching near Munich, Germany
- Catalysis Research Center, Technical University of Munich, Ernst-Otto-Fischer-Straße 1, D-85748 Garching near Munich, Germany
| | - Jens Neumann
- BMW Group, Development Powertrain, Schleißheimer 422, D-80937 Munich, Germany
| | - Olaf Hinrichsen
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, D-85748 Garching near Munich, Germany
- Catalysis Research Center, Technical University of Munich, Ernst-Otto-Fischer-Straße 1, D-85748 Garching near Munich, Germany
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Abstract
The production of new automotive catalytic converters requires the increase of the quantity of Platinum Group Metals in order to deal with the strict emission standards that are imposed for vehicles. The use of PGMs coming from the recycling of spent autocatalysts could greatly reduce the cost of catalyst production for the automotive industry. This paper presents the synthesis of novel automotive Three-Way Catalysts (PLTWC, Pd/Rh = 55/5, 60 gPGMs/ft3) and diesel oxidation catalysts (PLDOC, Pt/Pd = 3/1, 110 gPGMs/ft3) from recovered PGMs, without further refinement steps. The catalysts were characterized and evaluated in terms of activity in comparison with benchmark catalysts produced using commercial metal precursors. The small-scale catalytic monoliths were successfully synthesized as evidenced by the characterization of the samples with XRF analysis, optical microscopy, and N2 physisorption. Hydrothermal ageing of the catalysts was performed and led to a significant decrease of the specific surface area of all catalysts (recycled and benchmarks) due to sintering of the support material and metal particles. The TWCs were studied for their activity in CO and unburned hydrocarbon oxidation reactions under a slightly lean environment of the gas mixture (λ > 1) as well as for their ability to reduce NOx under a slightly rich gas mixture (λ < 1). Recycled TWC fresh catalyst presented the best performance amongst the catalysts studied for the abatement of all pollutant gases, and they also showed the highest Oxygen Storage Capacity value. Moreover, comparing the aged samples, the catalyst produced from recycled PGMs presented higher activity than the one synthesized with the use of commercial PGM metal precursors. The results obtained for the DOC catalysts showed that the aged PLDOC catalyst outperformed both the fresh catalyst and the aged DOC catalyst prepared with the use of commercial metal precursors for the oxidation of CO, hydrocarbons, and NO. The latter reveals the effect of the presence of several impurities in the recovered PGMs solutions.
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Gong J, Wang D, Li J, Kamasamudram K, Currier N, Yezerets A. An experimental and kinetic modeling study of aging impact on surface and subsurface oxygen storage in three-way catalysts. Catal Today 2019. [DOI: 10.1016/j.cattod.2017.11.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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The effect of hydrogen peroxide on properties of Ce 0.35 Zr 0.55 La 0.055 Pr 0.045 O 2 oxides and the catalytic performance used on Pd supported three-way catalyst. J RARE EARTH 2017. [DOI: 10.1016/j.jre.2017.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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