Gasoline automobile catalysis and its historical journey to cleaner air

Farrauto, Robert J.; Deeba, Michel; Alerasool, Saeed

doi:10.1038/s41929-019-0312-9

Cited by 170 publications

(98 citation statements)

References 77 publications

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“…Since the discovery of the strong metal-support interaction, there has been an explosion of investigations on reducible oxidesupported Pt catalysts to enhance the low-temperature activity, such as Pt/CeO 2 , Pt/FeO x , and Pt/Co 3 O 4 [10][11][12][13][14] . It has been demonstrated that the size of supported Pt catalysts is a key factor that affects the proportion of the interfacial active sites and interfacial interactions, directly correlating with the activity of Pt/ oxide catalysts 15 .…”

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confidence: 99%

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

et al. 2020

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Improving the low-temperature activity (below 100 °C) and noble-metal efficiency of automotive exhaust catalysts has been a continuous effort to eliminate cold-start emissions, yet great challenges remain. Here we report a strategy to activate the low-temperature performance of Pt catalysts on Cu-modified CeO2 supports based on redox-coupled atomic layer deposition. The interfacial reducibility and structure of composite catalysts have been precisely tuned by oxide doping and accurate control of Pt size. Cu-modified CeO2-supported Pt sub-nanoclusters demonstrate a remarkable performance with an onset of CO oxidation reactivity below room temperature, which is one order of magnitude more active than atomically-dispersed Pt catalysts. The Cu-O-Ce site with activated lattice oxygen anchors deposited Pt sub-nanoclusters, leading to a moderate CO adsorption strength at the interface that facilitates the low-temperature CO oxidation performance.

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confidence: 99%

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

et al. 2020

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“…CO oxidation is an important reaction for automotive catalysis, fuel cell applications, and it also serves as an ideal probe reaction for fundamental heterogeneous catalytic processes . Due to its importance in emission control, the catalytic oxidation of CO has been extensively studied, and the current generation of emission control catalysts are composed of a noble metal (Pt, Rh, Pd) supported on metal oxides . The catalytic properties of these supported noble metal catalysts are controlled by their size, shape and the interaction with the metal oxide support .…”

Section: Introductionmentioning

confidence: 99%

“…[3] Due to its importance in emission control, the catalytic oxidation of CO has been extensively studied, and the current generation of emission control catalysts are composed of a noble metal (Pt, Rh, Pd) supported on metal oxides. [4] The catalytic properties of these supported noble metal catalysts are controlled by their size, shape and the interaction with the metal oxide support. [5] Smaller sized clusters [6] and recently reported single atoms [7] provide the best utilization of the noble metals, and enhanced catalytic performance for CO oxidation has been shown in the nanometer and subnanometer regimes.…”

Section: Introductionmentioning

confidence: 99%

Origin of the High CO Oxidation Activity on CeO₂ Supported Pt Nanoparticles: Weaker Binding of CO or Facile Oxygen Transfer from the Support?

Thompson

Kunwar

et al. 2020

ChemCatChem

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Pt clusters supported on CeO2 are highly active for low temperature CO oxidation. The enhanced reactivity could be caused by weakening of the CO binding on Pt, allowing adsorbed oxygen to more effectively compete for sites. An alternative explanation is that interfacial sites allow adsorbed CO on Pt to react with lattice oxygen in the ceria. Here we explore the origins of enhanced CO oxidation reactivity on Pt/CeO2 using in‐situ/operando infrared and x‐ray spectroscopies, microcalorimetry, and reaction kinetics. We show that CO adsorbs strongly (∼110–120 kJ/mol) on Pt clusters (∼1.5 nm) and Pt is almost fully covered by CO during reaction, indicating that the high activity can be related to reactive interfacial O* species. Using in‐situ infrared spectroscopy we show that when the reaction mixture of CO and O2 stops flowing over the catalyst, the adsorbed CO on Pt is lost since it reacts with interfacial O*, but if this O* is depleted, the CO band does not disappear. The role of CeO2 is not to alter the binding of CO, but rather to enhance the reactivity of the interfacial metal‐support lattice oxygens. The reaction mechanism involving the interfacial Pt−CeO2 sites (two‐site mechanism) is further confirmed by kinetic measurements which show near zero order dependence on CO and O2 partial pressures.

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“…Sintering is a serious problem with supported metal catalysts in high-temperature applications, such as in automotive emissions control, because it leads to a loss of catalytically active surface area [1]. The concept of "intelligent" catalysts, in which the catalytic metals are supported on mixed oxides which have a perovskite structure, was developed as a possible solution to this problem [2].…”

Section: Introductionmentioning

confidence: 99%

“Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

et al. 2019

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LaCoO3 films were deposited onto MgAl2O4 powders by atomic layer deposition (ALD) and then used as catalyst supports for Pt. X-ray diffraction (XRD) showed that the 0.5 nm films exhibited a perovskite structure after redox cycling at 1073 K, and scanning transmission electron microscopy and elemental mapping via energy-dispersive X-ray spectroscopy (STEM/EDS) data demonstrated that the films covered the substrate uniformly. Catalysts prepared with 3 wt % Pt showed that the Pt remained well dispersed on the perovskite film, even after repeated oxidations and reductions at 1073 K. Despite the high Pt dispersion, CO adsorption at room temperature was negligible. Compared with conventional Pt on MgAl2O4, the reduced forms of the LaCoO3-containing catalyst were highly active for the CO oxidation and water gas shift (WGS) reactions, while the oxidized catalysts showed much lower activities. Surprisingly, the reduced catalysts were much less active than the oxidized catalysts for toluene hydrogen. Catalysts prepared from thin films of Co3O4 or La2O3 exhibited properties more similar to Pt/MgAl2O4. Possible reasons for how LaCoO3 affects properties are discussed.

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Gasoline automobile catalysis and its historical journey to cleaner air

Cited by 170 publications

References 77 publications

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

Origin of the High CO Oxidation Activity on CeO₂ Supported Pt Nanoparticles: Weaker Binding of CO or Facile Oxygen Transfer from the Support?

“Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

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Gasoline automobile catalysis and its historical journey to cleaner air

Cited by 170 publications

References 77 publications

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

Activation of subnanometric Pt on Cu-modified CeO2 via redox-coupled atomic layer deposition for CO oxidation

Origin of the High CO Oxidation Activity on CeO2 Supported Pt Nanoparticles: Weaker Binding of CO or Facile Oxygen Transfer from the Support?

“Intelligent” Pt Catalysts Based on Thin LaCoO3 Films Prepared by Atomic Layer Deposition

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Origin of the High CO Oxidation Activity on CeO₂ Supported Pt Nanoparticles: Weaker Binding of CO or Facile Oxygen Transfer from the Support?