Thermal deactivation of Pt/Rh commercial automotive catalysts

Fernandes, Daniela Meyer; Scofield, Cynthia Fraga; Neto, Arnaldo Alcover; Cardoso, Mauri José Baldini; Zotin, Fátima Marı́a Zanon

doi:10.1016/j.cej.2010.03.013

Cited by 45 publications

(9 citation statements)

References 42 publications

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“…Exothermic reactions can cause temperatures within the catalyst reaching higher than 1,000°C, causing thermal deactivation such as sintering of the precious metal particles. At high temperatures, the precious metal particles agglomerate, decreasing the surface area of catalyst available to reactant gases and therefore reducing the catalyst activity (Harris, 1995;Heck et al, 2002;Martin et al, 2003;Martinez-Arias et al, 2002;Meyer Fernandes et al, 2010;Polvinen et al, 2004;Tanabe et al, 2008;Winkler et al, 2010;Yang et al, 2008;Zanon Zotin et al, 2005). Sintering of the washcoat can also occur, with a decrease in surface area and a loss of internal pore structure.…”

Section: Introductionmentioning

confidence: 94%

“…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%

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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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Section: Introductionmentioning

confidence: 94%

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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“…In general, the world practice in the estimation of the TWC's lifetime shows that the faster and most informative way is the forced aging of TWC under various drastic conditions [4][5][6][7][8][9][10]. Such an approach allows the researchers to study the reasons and mechanisms of the catalysts' deactivation process [11][12][13][14][15][16]. During the last few decades, palladium was the most commonly studied precious metal, since the concept of Pd-only three-way catalyst was of high attractiveness.…”

Section: Introductionmentioning

confidence: 99%

Self-Regeneration Effect of Three-Way Catalysts during Thermal Aging Procedure

Alikin¹,

Denisov²,

Bubnov³

et al. 2020

Catalysts

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One of the most important features of the three-way catalysts is their long-term stability. However, quite often, promising catalytic compositions with excellent activity become deactivated after a relatively short period of exploitation due to various reasons. Therefore, a study on the onboard regeneration of the deactivated three-way catalysts remains its actuality. The present work is mainly focused on the self-regeneration effect of the rhodium-containing component. Aging of the catalysts in the standard and model engine braking regimes revealed the difference in the catalytic performance. Deactivated rhodium species turned to the active state as a result of rapid cooling in air flow from 1200 to 600 °C. The regenerated catalyst shows improved activity towards NOx reduction and, therefore, widened operation window, which indicates higher accessibility of the rhodium species. X-ray diffraction analysis of the aged catalysts does not reveal any noticeable phase changes. Contrary, significant changes in the Rh oxidation state were registered by X-ray photoelectron spectroscopy. The observed effect opens new horizons for the development of the onboard purification systems with prolonged exploitation lifetime.

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“…A desativação de catalisadores automotivos geralmente é um fenômeno complexo, principalmente quando envolve catalisadores comerciais, isso devido à presença de muitos componentes que desempenham diversos papéis em todo o sistema catalítico [6][7][8]. A perda de atividade catalítica e/ou seletividade ao longo do tempo é o resultado de uma série de mudanças químicas e físicas indesejadas [6,9].…”

Section: Introductionunclassified

Caracterização tecnológica de catalisadores automotivos desativados visando o aproveitamento de Pt, Pd e Rh

Baia¹,

Oliveira²,

Macêdo³

et al. 2020

Tecnol. Metal. Mater. Min.

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Baia et al. Publicado pela ABM. Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que o trabalho original seja corretamente citado. a Resumo A utilização de catalisadores automotivos vem aumentando nas últimas décadas. Com as rigorosas legislações de controle de emissões de gases poluentes, o número de catalisadores que são descartados também cresce, gerando enorme volume de resíduos, que podem ser uma fonte para a mineração urbana. O objetivo deste trabalho é caracterizar catalisadores automotivos desativados, em termos da composição mineralógica, estrutural e elementar, quantitativa e qualitativamente. As análises foram realizadas em granulometria por difração à laser, difratômetro de raios X (DRX), microscópio eletrônico de varredura com espectroscopia por dispersão de energia de raios X (MEV/EDS), espectroscopia Raman e espectrometria de emissão óptica em plasma com acoplamento indutivo (ICP-OES). O catalisador automotivo estudado apresentou fissuras e contaminantes como P, Ca, F, C e S, acentuando o processo de desativação. A maior composição identificada foi de cordierita, correspondendo 40,17%. Os metais catalíticos do grupo platina identificados no catalisador automotivo foram, Pd (0,92%), Pt (0,03%) e Rh (0,17%). Palavras-chave: Catalisadores automotivos; Caracterização; Cordierita; Grupo platina. Technological characterization of automotive catalysts disabled for Pt, Pd, and Rh recovery Abstracts The use of automotive catalysts has been increasing in recent decades. With the strict regulations governing the emission of polluting gases, the number of catalysts that are discarded also grows, generating enormous volume of waste, which can be a source for urban mining. The objective of this work is to characterize deactivated automotive catalysts in terms of mineralogical, structural and elemental composition, quantitatively and qualitatively. The analyzes were performed in granulometry by laser diffraction, X-ray diffractometer (XRD), scanning electron microscope with X-ray energy dispersion spectroscopy (SEM / EDS), Raman spectroscopy and inductive coupling plasma optical spectrometry (ICP-OES). The studied automotive catalyst presented cracks and contaminants such as P, Ca, F, C and S, accentuating the deactivation process. The largest composition identified was cordierite, corresponding to 40.17%. The catalysts of the platinum group identified in the automotive catalyst were, Pd (0.92%), Pt (0.03%) and Rh (0.17%).

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Thermal deactivation of Pt/Rh commercial automotive catalysts

Cited by 45 publications

References 42 publications

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

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

Self-Regeneration Effect of Three-Way Catalysts during Thermal Aging Procedure

Caracterização tecnológica de catalisadores automotivos desativados visando o aproveitamento de Pt, Pd e Rh

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