Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst

More, Karren L.; Kenik, E.A.; Coffey, D. W.; Geer, T.S.; LaBarge, W.; Beckmeyer, R.; Theis, Joseph R.

doi:10.4271/972905

Cited by 9 publications

(4 citation statements)

References 14 publications

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“…Operation of TWC under extremely harsh conditions (T > 850 °C) can cause deactivation of the catalyst, a phenomenon called thermal ageing, presenting a decreased conversion efficiency and higher light-off temperatures. Thermal ageing is linked to the modification of the washcoat structure, called sintering, following by a loss of active surface area via structural modification of the porous support with a decrease of surface area of the carrier [ 31 , 32 ]. As a result, stringent emissions standards require high efficiency in emissions abatement and catalyst performance at high mileage [ 33 ].…”

Section: Resultsmentioning

confidence: 99%

PROMETHEUS: A Copper-Based Polymetallic Catalyst for Automotive Applications. Part II: Catalytic Efficiency an Endurance as Compared with Original Catalysts

Yakoumis¹,

Polyzou²,

Moschovi³

2021

Materials

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PROMETHEUS catalyst, a copper-based polymetallic nano-catalyst has been proven to be suitable for automotive emission control applications. This novel catalyst consists of copper, palladium and rhodium nanoparticles as active phases, impregnated on an inorganic oxide substrate, CeO2/ZrO2 (75%, 25%). The aim of PROMETHEUS catalyst’s development is the substitution of a significant amount (85%) of Platinum Group Metals (PGMs) with copper nanoparticles while, at the same time, presenting high catalytic efficiency with respect to the commercial catalysts. In this work, an extensive investigation of the catalytic activity of full scale PROMETHEUS fresh and aged catalyst deposited on ceramic cordierites is presented and discussed. The catalytic activity was tested on an Synthetic Gas Bench (SGB) towards the oxidation of CO and CH4 and the reduction of NO. The loading of the washcoat was 2 wt% (metal content) on Cu, Pd, Rh with the corresponding metal ratio at 21:7:1. The concentration of the full-scale monolithic catalysts to be 0.032% total PGM loading for meeting Euro III standard and 0.089% for meeting Euro IV to Euro VIb standards. The catalytic activity of all catalysts was tested both in rich-burn (λ = 0.99) and lean-burn conditions (λ = 1.03).

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Section: Resultsmentioning

confidence: 99%

PROMETHEUS: A Copper-Based Polymetallic Catalyst for Automotive Applications. Part II: Catalytic Efficiency an Endurance as Compared with Original Catalysts

Yakoumis¹,

Polyzou²,

Moschovi³

2021

Materials

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“…Sintering of the washcoat can also occur, with a decrease in surface area and a loss of internal pore structure. The washcoat undergoes irreversible phase changes, with the alumina washcoat transforming from the gamma phase, γ-Al 2 O 3 , through delta, δ-Al 2 O 3 and theta, θ-Al 2 O 3 , to the stable alpha alumina, α-Al 2 O 3 , with loss of surface area and hence loss of catalyst activity (Heck et al, 2002;Martinez-Arias et al, 2002;Meyer Fernandes et al, 2010;More et al, 1997;Zanon Zotin et al, 2005). Catalyst deactivation can also be caused by catalyst poisoning, which can occur by two mechanisms.…”

Section: Introductionmentioning

confidence: 97%

Correlation of light-off activity for full size and cored catalyst samples

Blades

Douglas

McCullough

et al. 2016

IJPT

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This study identifies, and analyses, the correlation that exists in the CO light-off performance of full size canned catalytic converters and cored samples taken from the front and rear sections of the same catalyst brick. Testing was conducted under laboratory conditions, with full size samples tested using the Catagen Labcat, and testing of cored samples conducted using the Horiba SIGU 2000. From experimental tests alone, there was no clear correlation between the CO light-off activities of full size and cored catalyst samples. However, by performing simulations using the QUB global catalyst model, which accounts for the variation of precious metal dispersion and differences in the heat transfer characteristics of the test rigs, correlation was shown to be good. . During this work, he investigated the change in catalyst activity due to static and dynamic ageing, and used mathematical catalyst modelling to identify correlation between full size bricks and cored catalyst samples. His other research areas of interest include waste heat recovery. Correlation of light-off activity for full size and cored catalyst samples149 Roy Douglas is a Professor of IC Engines Technology and Director of Clean Energy Research in Mechanical Engineering at Queen's University, Belfast. He has over 35 years experience in the areas of engine research and development, systems modelling and automotive after-treatment. For the past ten years, his research has concentrated on automotive drive cycles and systems energy management, with particular emphasis on bus applications such as hybrid electric vehicles and thermal management of heavy duty powertrains. He is a senior member of the School of Mechanical and Aerospace Engineering and a member of the management board.Geoffrey McCullough is a Senior Lecturer at Queen's University Belfast. He completed his PhD degree in 1997 on the subject of reaction kinetics within automotive catalysts. The main focus of his research is the reduction of emissions from automotive engines, which includes theoretical model development combined with experimental validation. He has published 65 papers in peer-reviewed journals and international conferences on this subject. He is an academic partner of the Centre for the Theory and Application of Catalysis (CenTACat) and teaches the internal combustion engines courses on both the Bachelor's and Master's degree programs.Andrew Woods is the CEO and co-founder of Catagen. He received both his Master's and PhD in Mechanical Engineering from Queen's University Belfast. His PhD degree (ageing and characterisation of automotive catalysts) culminated in the co-development of the original prototype that evolved into Catagen's product range. He holds two patents as co-inventor, one of which protects the innovation in the Catagen products. He, co-author on a number of papers, continues research within the Catagen organisation, making regular discoveries related to after treatment system development. He is extensively travelled and has participated in entrepreneurship train...

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“…Therefore, comprehensive study is required on automotive catalysts deactivation as a function of vehicle mileage. It has been shown that there are many independent processes that collectively contribute to catalyst deactivation [14]. The most important of them are chemical and thermal mechanisms [15,16].…”

Section: Introductionmentioning

confidence: 99%

Mileage Influence on Conversion Efficiency of Catalytic Converter from In-Use Vehicles

Tartakovsky

Baibikov

Veinblat

et al. 2012

SAE Int. J. Engines

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Although many works are published about the achieved advancements in the manufacturing of the catalytic converters (CC) system for vehicle engines and their testing under laboratory conditions, there is a lack in the published research about the mileages influence on their conversion efficiency (CE). Dependence of dual-brick CCs' CE in real-world driving conditions on vehicle mileage is studied for the first time. The CC tested are dismantled from the vehicles with mileage from 0 (new one) up to 150000 km. The studied CC are evaluated at the engine test bench containing a dynamometer coupled with a spark ignition engine suitable for this type of CC system. Measurements of CC efficiency are performed at four different engine operation regimes: two loaded regimes and two non-load regimes -low and high speed idling. It is found that the oxidation of CO and HC at all four tested regimes took place almost totally in the first CC. Under higher engine loads the conversion of NO x also took place mainly in the first CC. The overall efficiency of conversion reaches values above 99% for most of the tested systems. No significant degradation of CE is found in the studied vehicle mileage range. CE of the CC system that has accumulated the highest mileage, of almost 150000 km, reaches values of 97-99% for CO, 86-99% for HC and 64-99% for NOx at the loaded testing regimes. The smaller values are obtained for the low load regime when the CC temperature is decreased. Considering that the European legislation imposes a durability of 160000 km for the CCs, the results obtained in this work show that for the mileage of 150000 km CC keep a very high CE rate. The CC system that included an aftermarket non-genuine CC is the only one, where significant catalyst deactivation is observed. Registered values of the backpressure do not show any of the tested CC systems as being clogged.

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Thermally-Induced Microstructural Changes in a Three-Way Automotive Catalyst

Cited by 9 publications

References 14 publications

PROMETHEUS: A Copper-Based Polymetallic Catalyst for Automotive Applications. Part II: Catalytic Efficiency an Endurance as Compared with Original Catalysts

PROMETHEUS: A Copper-Based Polymetallic Catalyst for Automotive Applications. Part II: Catalytic Efficiency an Endurance as Compared with Original Catalysts

Correlation of light-off activity for full size and cored catalyst samples

Mileage Influence on Conversion Efficiency of Catalytic Converter from In-Use Vehicles

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