Calibration of the Oxygen Storage Reactions for the Modeling of an Automotive Three-Way Catalyst

2021 ◽  
Author(s):  
Augusto Della Torre ◽  
Gianluca Montenegro ◽  
Angelo Onorati ◽  
Stefano Paltrinieri ◽  
Federico Rulli ◽  
...  
Keyword(s):  
Oxygen Storage ◽  
Three Way Catalyst

scholarly journals Modeling of Three-Way Catalyst Dynamics for a Compressed Natural Gas Engine during Lean–Rich Transitions

2019 ◽  
Vol 9 (21) ◽  
pp. 4610 ◽  
Author(s):  
Dario Di Maio ◽  
Carlo Beatrice ◽  
Valentina Fraioli ◽  
Pierpaolo Napolitano ◽  
Stefano Golini ◽  
...  
Keyword(s):  
Steady State ◽  
Natural Gas ◽  
Catalytic Converter ◽  
Operating Conditions ◽  
Oxygen Storage ◽  
Continuous Control ◽  
Engine Exhaust ◽  
Compressed Natural Gas ◽  
The Impact ◽  
Three Way Catalyst

The main objective of the present research activity was to investigate the effect of very fast composition transitions of the engine exhaust typical in real-world driving operating conditions, as fuel cutoff phases or engine misfire, on the aftertreatment devices, which are generally very sensitive to these changes. This phenomenon is particularly evident when dealing with engines powered by natural gas, which requires the use of a three-way catalyst (TWC). Indeed, some deviations from the stoichiometric lambda value can interfere with the catalytic converter efficiency. In this work, a numerical “quasi-steady” model was developed to simulate the chemical and transport phenomena of a specific TWC for a compressed natural gas (CNG) heavy-duty engine. A dedicated experimental campaign was performed in order to evaluate the catalyst response to a defined λ variation pattern of the engine exhaust stream, thus providing the data necessary for the numerical model validation. Tests were carried out to reproduce oxygen storage phenomena that make catalyst behavior different from the classic steady-state operating conditions. A surface reaction kinetic mechanism concerning CH4, CO, H2, oxidation and NO reduction has been appropriately calibrated at different λ values with a step-by-step procedure, both in steady-state conditions of the engine work plan and during transient conditions, through cyclical and consecutive transitions of variable frequency between rich and lean phases. The activity also includes a proper calibration of the reactions involving cerium inside the catalyst in order to reproduce oxygen storage and release dynamics. Sensitivity analysis and continuous control of the reaction rate allowed evaluating the impact of each of them on the exhaust composition in several operating conditions. The proposed model predicts tailpipe conversion/formation of the main chemical species, starting from experimental engine-out data, and provides a useful tool to evaluate the catalyst’s performance.

Overview: Modification of Cerium Oxide in Three-Way Catalysts

2014 ◽  
Vol 575 ◽  
pp. 97-102 ◽  
Author(s):  
M. Nazri Abu Shah ◽  
S. Hanim Md Nor ◽  
Kamariah Noor Ismail ◽  
Abdul Hadi
Keyword(s):  
Thermal Stability ◽  
Rare Earth ◽  
Metal Oxides ◽  
Cerium Oxide ◽  
Storage Capacity ◽  
Rare Earth Metals ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
Alkaline Metals ◽  
Three Way Catalyst

An overview of modification of cerium oxide, CeO2which is employed in the three-way catalyst (TWCs) is presented in this article. The modifications of cerium oxide, CeO2incorporated with the metal oxides for the improvement of thermal stability, microstructure and oxygen storage capacity (OSC) are discussed. In view of that, the types of metal oxide are grouped into transition metals, rare earth metals, and alkaline metals and the effect of each group into cerium oxide, CeO2are elaborated.

scholarly journals Visualization of Heterogeneous Oxygen Storage Behavior in Platinum-Supported Cerium-Zirconium Oxide Three-Way Catalyst Particles by Hard X-ray Spectro-Ptychography

2018 ◽  
Vol 57 (6) ◽  
pp. 1474-1479 ◽  
Author(s):  
Makoto Hirose ◽  
Nozomu Ishiguro ◽  
Kei Shimomura ◽  
Nicolas Burdet ◽  
Hirosuke Matsui ◽  
...  
Keyword(s):  
Zirconium Oxide ◽  
Oxygen Storage ◽  
X Ray ◽  
Storage Behavior ◽  
Three Way Catalyst

The Effect of Grid Resolution and Oxygen Storage in a One-Dimensional Monolithic Three-Way Catalyst Model

2009 ◽  
Vol 42 (26) ◽  
pp. 191-198 ◽  
Author(s):  
Denis I. Andrianov ◽  
Robert J. Dingli ◽  
Michael J. Brear ◽  
Chris Manzie
Keyword(s):  
Grid Resolution ◽  
Oxygen Storage ◽  
One Dimensional ◽  
Three Way Catalyst ◽  
Catalyst Model

Towards ECU-Executable Control-Oriented Models of a Three-Way Catalytic Converter

2015 ◽  
Author(s):  
Mario Santillo ◽  
Steve Magner ◽  
Mike Uhrich ◽  
Mrdjan Jankovic
Keyword(s):  
Catalytic Converter ◽  
Control Unit ◽  
Oxygen Storage ◽  
Exhaust Gas ◽  
Sensor Model ◽  
Vehicle Engine ◽  
Robust Model ◽  
Combined Models ◽  
Automated Optimization ◽  
Three Way Catalyst

The nonlinear dynamics of an automotive three-way catalyst (TWC) present a challenge to developing simple control-oriented models that are both useful for control and/or diagnostics and real-time executable within a vehicle engine-control unit (ECU). As such, we begin by developing a first-principles control-oriented TWC model and then proceed to apply simplifications. The TWC models are spatially discretized along the catalyst length to better understand and exploit the oxygen-storage dynamics. The TWC models also include the oxidation reaction of ceria by H2O, which is considered important since it represents the production of H2 within the catalyst. We present automated optimization routines to calibrate the TWC model along with a heated exhaust-gas oxygen (HEGO) sensor model using measured vehicle and emissions data. Finally, we demonstrate the combined models’ ability to accurately reproduce the measured HEGO voltage using engine feedgas constituent inputs, which is necessary for designing a robust model-based feedback controller.

Thermal Stability Study of Ce0.75-Zr0.25O Nanostructures Synthesized via Water-in-Oil Microemulsion Method

2013 ◽  
Vol 701 ◽  
pp. 207-211 ◽  
Author(s):  
Nur Azrani M. Jani ◽  
Abdul Hadi ◽  
Kamariah Noor Ismail
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Solid Solution ◽  
Elevated Temperatures ◽  
Xrd Analysis ◽  
Oxygen Storage ◽  
Microemulsion Method ◽  
Surface Areas ◽  
Wide Range ◽  
Three Way Catalyst

Fundamentally, ceria particle had ability to store, transport and release oxygen, which was identified as oxygen storage capacity (OSC). Due to this OSC ability, ceria became the most important component in the three-way catalyst. With the addition of zirconia into the ceria resulting in better performance in three-way catalyst as it increased or improved thermal stability and also promotes the redox properties. This study was conducted to investigate the effects of heat treatment on the structure and physical property of nanocrystalline Ce-Zr-O solid solution. Microemulsion method was used for preparation of Ce-Zr-O solid solution, and heat treatment investigation was applied towards the synthesized nanocrystalline Ce-Zr-O solid solution. The phase and crystal structure of Ce-Zr-O solid solution were determined using XRD analysis. While, the modification of surface area and porosity size over the wide range of calcination temperatures range from 300°C to 700°C was investigated using BET Analyzer. XRD analysis confirmed the Ce0.75Zr0.25O2 solid solution was succesfully synthesized in the research. The results exhibited the effect of heat treatment on the decreasing of surface areas and porosity profiles of the Ce0.75Zr0.25O2. Despite of the reduction of surface areas at elevated temperatures, the study found the promising results that the enhancement of thermal stability of ceria by addition of zirconia.

scholarly journals Aspects of Dynamic Three-Way Catalyst Behaviour Including Oxygen Storage

2004 ◽  
Vol 37 (22) ◽  
pp. 331-336 ◽  
Author(s):  
Theophil S. Auckenthaler ◽  
Christopher H. Onder ◽  
Hans P. Geering
Keyword(s):  
Oxygen Storage ◽  
Three Way Catalyst
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