Ideal Pt loading for a Pt/CeO2-based catalyst stabilized by a Pt–O–Ce bond

Hatanaka, Miho; Takahashi, Naoki; Tanabe, Toshitaka; Nagai, Yasutaka; Dohmae, Kazuhiko; Aoki, Yuki; Yoshida, Takahiro; Shinjoh, Hirofumi

doi:10.1016/j.apcatb.2010.07.003

Cited by 116 publications

(83 citation statements)

References 35 publications

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“…It is difficult to evaluate the exact value but rough estimation can be made basing on EDS data. A 3 wt.% Rh 2 O 3 content and mean crystallite size of ceria À37 nm, (corresponding to 23 m 2 /g surface area) would give a value $10 times higher than a value of 0.25 g Pt for 100 g of CeO 2 (surface area 30 m 2 /g) reported as maximum, monolayer surface coverage for thermally stable Pt-O-Ce surface phase [33]. It should be remembered however that in our case Rh is distributed not only at the surface but also within the bulk of ceria.…”

Section: Heating In Oxidizing Atmospherementioning

confidence: 94%

Structure and thermal stability of nanocrystalline Ce1−xRhxO2−y in reducing and oxidizing atmosphere

Kurnatowska

Kępiński

2013

Materials Research Bulletin

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Section: Heating In Oxidizing Atmospherementioning

confidence: 94%

Structure and thermal stability of nanocrystalline Ce1−xRhxO2−y in reducing and oxidizing atmosphere

Kurnatowska

Kępiński

2013

Materials Research Bulletin

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“…101,102 In the real Pt-CeO 2 catalysts, excess O atoms may also be incorporated during the synthesis that proceeds in air. 103,104 Most importantly, it was found that the relative abundance of the Pt 2+ and Pt 0 species depends on the density of steps and the number of oxygen vacancies in the CeO 2 Ĳ111) film. In particular, the amount of Pt 2+ species scales linearly with the step density.…”

Section: Stability As a Function Of Noble Metal Loadingmentioning

confidence: 99%

“…156 In this respect the ideal Pt loading should allow full recovery of the atomically dispersed state. 104 It is likely that the degree of stabilization and the strong dependence of the catalytic activity (power density) on Pt loading observed for the Pt-CeO 2 anode fuel cell catalysts are associated with the degree of reversibility that can be achieved in the catalyst film. 41 …”

Section: Structural Flexibility Of Sub-nanometer Metal Particlesmentioning

confidence: 99%

Oxide-based nanomaterials for fuel cell catalysis: the interplay between supported single Pt atoms and particles

Lykhach

Bruix

Fabris

et al. 2017

Catal. Sci. Technol.

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The concept of single atom catalysis offers maximum noble metal efficiency for the development of lowcost catalytic materials. Among possible applications are catalytic materials for proton exchange membrane fuel cells. In the present review, recent efforts towards the fabrication of single atom catalysts on nanostructured ceria and their reactivity are discussed in the prospect of their employment as anode catalysts.The remarkable performance and the durability of the ceria-based anode catalysts with ultra-low Pt loading result from the interplay between two states associated with supported atomically dispersed Pt and subnanometer Pt particles. The occurrence of these two states is a consequence of strong interactions between Pt and nanostructured ceria that yield atomically dispersed species under oxidizing conditions and sub-nanometer Pt particles under reducing conditions. The square-planar arrangement of four O atoms on {100} nanoterraces has been identified as the key structural element on the surface of the nanostructured ceria where Pt is anchored in the form of Pt 2+ species. The conversion of Pt 2+ species to subnanometer Pt particles is triggered by a redox process involving Ce 3+ centers. The latter emerge due to either oxygen vacancies or adsorption of reducing agents. The unique properties of the sub-nanometer Pt particles arise from metal-support interactions involving charge transfer, structural flexibility, and spillover phenomena. The abundance of specific adsorption sites similar to those on {100} nanoterraces determines the ideal (maximum) Pt loading in Pt-CeO x films that still allows reversible switching between the atomically dispersed Pt and sub-nanometer particles yielding high activity and durability during fuel cell operation.

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“…Furthermore, very small metal clusters with electronic quantum size effects, in other words the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap, lead to lower activation barriers of the reaction, which have a decisive role in the increase of reactivity [48]. Therefore, the very small metal clusters, especially isolated single atoms, anchored on the supports represent a new type of catalyst with a superior catalytic performance for various reactions [5,[8][9][10]. Thus, the 0.2 Pd/ZrO 2 with an average Pd cluster size of 1.0 nm shows higher catalytic activities for Arrhenius-type plots of the selective hydrogenation of SUC over the Pd/ZrO 2 catalysts are shown in Figure 3 and the activation energy (Ea) was calculated based on initial reaction rates measured at different temperatures.…”

Section: Catalytic Activity Of Pd/zromentioning

confidence: 99%

“…However, the stability and recyclability remain a challenge because the isolated clusters or single atoms are mobile and readily sintered under high reaction temperatures [7]. To the best of our knowledge, there are only a few contributions regarding the atomically dispersed Pd catalysts that are active and stable at high temperatures [8,9], while those of Au and Pt catalysts have been widely reported [10][11][12][13]. Atomically dispersed Pd on graphene shows excellent durability against deactivation during 100 h of reaction time [8].…”

Section: Introductionmentioning

confidence: 99%

Regenerable Subnanometer Pd Clusters on Zirconia for Highly Selective Hydrogenation of Biomass-Derived Succinic Acid in Water

Zhang¹,

Cao²,

Cheng³

et al. 2016

Catalysts

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Abstract:The size of metal particles is an important factor to determine the performance of the supported metal catalysts. In this work, we report subnanometer Pd clusters supported on zirconia by the microwave-assisted hydrothermal method. The presence of subnanometer Pd clusters on the zirconia surface was confirmed by two-dimensional Gaussian-function fits of the aberration-corrected high-angle annual dark-field images. These subnanometer Pd catalysts exhibit high catalytic performance for the hydrogenation of biomass-derived succinic acid to γ-butyrolactone in water and avoid the formation of overhydrogenated products, such as 1,4-butanediol and tetrahydrofuran. The catalyst with an ultra-low Pd loading of 0.2 wt. % demonstrated high selectivity (95%) for γ-butyrolactone using water as a solvent at 473 K and 10 MPa. Moreover, it can be reused at least six times without the loss of catalytic activity, illustrating high performance of the small Pd clusters.

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Ideal Pt loading for a Pt/CeO2-based catalyst stabilized by a Pt–O–Ce bond

Cited by 116 publications

References 35 publications

Structure and thermal stability of nanocrystalline Ce1−xRhxO2−y in reducing and oxidizing atmosphere

Structure and thermal stability of nanocrystalline Ce1−xRhxO2−y in reducing and oxidizing atmosphere

Oxide-based nanomaterials for fuel cell catalysis: the interplay between supported single Pt atoms and particles

Regenerable Subnanometer Pd Clusters on Zirconia for Highly Selective Hydrogenation of Biomass-Derived Succinic Acid in Water

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