The Effect of Pt:Pd Ratio on Heavy-Duty Diesel Oxidation Catalyst Performance: An Experimental and Modeling Study

Shakya, Bijesh M.; Sukumar, Balaji; Jesús, Yaritza M. López-De; Markatou, Penelope

doi:10.4271/2015-01-1052

Cited by 36 publications

(19 citation statements)

References 10 publications

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“…In order to identify adsorbed species and possible differences in the oxidation states of the monometallic versus bimetallic samples, in situ DRIFTS experiments were performed using a Nicolet 6700 spectrometer equipped with a MCT detector and a high temperature Harrick Scientific Praying Mantis reaction chamber with ZnSe windows. 30 mg of catalyst was mixed 9 with an equal amount of KBr to form the sample. The DRIFTS spectra were collected in the 4000-650 cm -1 wavenumber range, accumulating 98 scans at 4 cm -1 resolution.…”

Section: Diffuse Reflectance Infrared Fourier Transform Spectroscopy mentioning

confidence: 99%

“…[8] As an example, in a previous DOC study it was shown that a higher Pt content in bimetallic Pt/Pd catalysts led to better (lower temperature) NO, decane and propylene oxidation, while catalysts with a higher Pd content led to improved CO oxidation performance. [9] Understanding and predicting this bimetallic behavior has proven challenging as to date no apparent relationship exists between the metal properties and 4 catalyst performance. [5] Due to the high CO and HC concentrations in LTC engine exhaust discussed above, more emphasis needs to be placed on understanding the Pt and Pd activity in the DOC.…”

Section: Introductionmentioning

confidence: 99%

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Kinetic and mechanistic study of bimetallic Pt-Pd/Al2O3 catalysts for CO and C3H6 oxidation

Hazlett

Moses-DeBusk

Parks

et al. 2017

Applied Catalysis B: Environmental

114

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Low temperature combustion (LTC) diesel engines are being developed to meet increased fuel economy demands. However, some LTC engines emit higher levels of CO and hydrocarbons and therefore diesel oxidation catalyst (DOC) efficiency will be critical. Here, CO and propylene oxidation were studied, as representative LTC exhaust components, over model bimetallic Pt-Pd/γ-Al2O3 catalysts. During CO oxidation tests, monometallic Pt suffered the most extensive inhibition which was correlated to a greater extent of dicarbonyl species formation. Pd and Pd-rich bimetallics were inhibited by carbonate formation at higher temperatures. The 1:1 and 3:1 Pt:Pd bimetallic catalysts did not form the dicarbonyl species to © 2016. This manuscript version is made available under the Elsevier user license http://www.elsevier.com/open-access/userlicense/1.0/ 2 the same extent as the monometallic Pt sample, and therefore did not suffer from the same level of inhibition. Similarly they also did not form carbonates to as large an extent as the Pdrich samples and were therefore not as inhibited from this intermediate surface species at higher temperature. The Pd-rich catalysts were relatively poor propylene oxidation catalysts;and partial oxidation product accumulation deactivated these catalysts. Byproducts observed include acetone, ethylene, acetaldehyde, acetic acid, formaldehyde and CO. For CO and propylene co-oxidation, the onset of propylene oxidation was not observed until complete CO oxidation was achieved, and the bimetallics showed higher activity. This was again related to less extensive poisoning, less dicarbonyl species formation and less overall partial oxidation product accumulation.

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Section: Diffuse Reflectance Infrared Fourier Transform Spectroscopy mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Kinetic and mechanistic study of bimetallic Pt-Pd/Al2O3 catalysts for CO and C3H6 oxidation

Hazlett

Moses-DeBusk

Parks

et al. 2017

Applied Catalysis B: Environmental

114

View full text Add to dashboard Cite

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“…Adding both Pt and Pd in a DOC is beneficial due to enhanced bimetallic catalytic activity as well as reduced sintering, i.e., greater longevity . This introduces another parameter: instead of changing the loading of one certain catalytic component axially, zoning different Pt‐Pd bimetallic ratios can also improve catalytic activity.…”

Section: Layered and Zoned Diesel Oxidation Catalyst (Doc)mentioning

confidence: 99%

Heterogeneous catalyst design: Zoned and layered catalysts in diesel vehicle aftertreatment monolith reactors

Hazlett

Epling

2018

Can J Chem Eng

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There have been ongoing research efforts focused on layering or zoning different washcoats/active metals on the catalysts constituting diesel aftertreatment systems: the diesel oxidation catalyst (DOC), the selective catalytic reduction (SCR) catalyst, the lean NOX trap (LNT), the ammonia slip catalyst (ASC), and the diesel particulate filter (DPF). This review paper aims to shed insight into the state‐of‐the‐art research on catalyst design in this area and how these catalyst designs may evolve to tackle engine emission reductions in the future. First, we discuss the motivation for zoning or layering catalysts and pioneering work on three‐way catalyst (TWC) design for reducing gasoline engine emissions; then, we focus on the catalytic systems used for diesel exhaust aftertreatment. The configuration of the aftertreatment systems for diesel engines generally consist of an oxidation catalyst for hydrocarbon (HC), CO, and NO oxidation (over the DOC), a NOX reduction catalyst (over one or combined SCR/LNT/ASC catalysts), and a particulate matter (PM) filter (using a DPF). The research to date consistently demonstrates that zoning and layering catalyst regions leads to improved performance and/or smaller system volumes required.

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“…Among them, Pt is widely used in DOCs, and the addition of Pd was shown to increase the thermal stability and sintering resistance of the catalyst [1]. As PGMs are high cost components of ATSs, several efforts have concentrated on decreasing the amount of PGMs and increasing the stability and efficiency of PGMs by preparing DOCs with different PGM loadings, ratios, or particle sizes [3][4][5][6][7][8][9][10], and using different synthesis techniques [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Preparation of Pt/Al2O3 and PtPd/Al2O3 catalysts by supercritical deposition and their performance for oxidation of nitric oxide and propene

et al. 2022

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The Effect of Pt:Pd Ratio on Heavy-Duty Diesel Oxidation Catalyst Performance: An Experimental and Modeling Study

Cited by 36 publications

References 10 publications

Kinetic and mechanistic study of bimetallic Pt-Pd/Al2O3 catalysts for CO and C3H6 oxidation

Kinetic and mechanistic study of bimetallic Pt-Pd/Al2O3 catalysts for CO and C3H6 oxidation

Heterogeneous catalyst design: Zoned and layered catalysts in diesel vehicle aftertreatment monolith reactors

Preparation of Pt/Al2O3 and PtPd/Al2O3 catalysts by supercritical deposition and their performance for oxidation of nitric oxide and propene

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