A comparison of hierarchical Pt@CeO2/Si–Al2O3 and Pd@CeO2/Si–Al2O3

Arroyo‐Ramírez, Lisandra; Chen, Chen; Cargnello, Matteo; Murray, Christopher B.; Gorte, Raymond J.

doi:10.1016/j.cattod.2015.01.036

Cited by 8 publications

(8 citation statements)

References 28 publications

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“…Agglomerates of PdO and CeO 2 nanoparticles were observed in our previous work, although a different method of synthesis was employed . Similar core‐shell structures have been reported in other works …”

Section: Discussionsupporting

confidence: 86%

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

et al. 2019

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Structural transformations in Pd/CeO 2 catalysts during their calcination over a wide temperature range (450-1200°C) were studied with structural, spectroscopic, and kinetic methods (XRD, TEM, XPS, and TPR). Two synthetic methods were applied: coprecipitation and incipient wetness impregnation. The impregnation synthesis produced the best low-temperature oxidation of CO (LTO CO) for the catalysts that were calcined at 450-900°C. Their high LTO CO activities could be attributed to the formation of reactive surface clusters at the PdOÀ CeO 2 interface. The coprecipitation synthesis produced a homoge-neous Pd x Ce 1-x O 2-δ solid solution with no Pd nanostructured particles. Decomposition of the solid solution phase occurred at 800-850°C and resulted in the formation of unusual Pd species, i. e., Pd(Ce)O x superstructures and agglomerates consisting of 2 nm PdO particles. Further calcination of the catalysts resulted in the formation of mixed Pd 0 À PdOÀ CeO 2 nanoparticles with a heterophase morphology that provided high thermal stability. These catalysts demonstrated capability for CO oxidation at temperatures below 100°C after calcination at 1200°C.

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Section: Discussionsupporting

confidence: 86%

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

et al. 2019

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“…39 At higher temperature, formates are further converted and become intermediates in the catalytic process, 39 while sintering of Pt is considered the main reason for catalyst deactivation. 38 In order to hinder Pt sintering, hierarchical Pt@CeO 2 /Si-Al 2 O 3 samples were prepared from self-assembled core-shell nanoparticles, 40 obtaining stable catalytic activity aer pre-treatment of the catalyst at 500 C. Differently from Pt, Pd@CeO 2 /Si-Al 2 O 3 demonstrates a fast decrease of the catalytic activity, 40,41 mainly because of an electronic inuence due to reduced CeO 2Àx and the partial occlusion of Pd nanoparticles within CeO 2Àx crystallites. 41 To overcome these problems, Pd@CeO 2 /MWCNT hybrid materials have been synthesized, observing that the balance between the organic and inorganic components favors their electronic interaction, nally leading to stable catalytic performances in the WGSR.…”

Section: Wgsr Activitymentioning

confidence: 99%

The water gas shift reaction over Pt–CeO₂ nanoparticles confined within mesoporous SBA-16

et al. 2017

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Novel nanocomposite catalysts for the single step Water Gas Shift Reaction (WGSR) were prepared by deposition–precipitation and impregnation of Pt–CeO2 nanophases onto an ordered mesoporous silica support featuring a cubic arrangement of mesopores (SBA-16 type). The highly interconnected porosity of the SBA-16 developed in three dimensions (3D) provides a scaffold which is easily accessible to reactants and products by diffusion. The textural and morphological properties of the final catalyst were affected by the procedure utilized for dispersion of the nanophases onto SBA-16. The catalysts prepared by deposition–precipitation present highly dispersed nanocrystalline CeO2 on the surface of SBA-16 and retain a high surface area, high thermal stability and high Pt accessibility. The catalysts prepared by impregnation show improved Pt–CeO2 interaction but a more significant decrease of surface area compared to pure SBA-16, due to the confinement of the CeO2 crystallites within the mesoporous matrix. As a result, the catalysts prepared by deposition–precipitation are effective for the WGSR under working conditions in the high temperature range (around 300–350 °C), whereas the catalysts prepared by impregnation are suitable for the process operating at low temperature. Our results point out that these catalyst preparation procedures can be used to optimise the performance of heterogenous catalysts, by controlling the CeO2 crystallite size and optimizing the Pt–CeO2 contact by embedding. Improved thermal and chemical stabilities were achieved using a mesoporous scaffold

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“…Over the past several decades, different types of catalysts have been developed for low-temperature methane combustion . These include noble metal-based (e.g., Pd, − Pt, − and Au , ), metal oxide-based (e.g., CuO, Co 3 O 4 , CeO 2 , and MnO x ), perovskite, spinel, and hexa-aluminate catalysts . Among them, Pd-based catalysts are some of the best for methane conversion .…”

Section: Introductionmentioning

confidence: 99%

Mesoporous Silica-Supported Nanostructured PdO/CeO₂ Catalysts for Low-Temperature Methane Oxidation

Dai

Kumar

Zhu

et al. 2017

ACS Appl. Mater. Interfaces

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Nanostructured PdO/CeO supported on mesoporous SBA-15 silica was synthesized using a combination of incipient wetness impregnation and surface-assisted reduction. After calcination, the materials showed good activity as catalysts for the low-temperature oxidation of methane, with a sample having 5 wt % Pd loading showing 50% conversion to CO at ∼290 °C and complete conversion below 360 °C. The stability of catalysts in the presence of water was studied. The formation of Pd(0) during the methane oxidation reaction increases the oxygen vacancies on the surface of catalysts, improving the catalytic activity.

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A comparison of hierarchical Pt@CeO2/Si–Al2O3 and Pd@CeO2/Si–Al2O3

Cited by 8 publications

References 28 publications

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

The water gas shift reaction over Pt–CeO₂ nanoparticles confined within mesoporous SBA-16

Mesoporous Silica-Supported Nanostructured PdO/CeO₂ Catalysts for Low-Temperature Methane Oxidation

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A comparison of hierarchical Pt@CeO2/Si–Al2O3 and Pd@CeO2/Si–Al2O3

Cited by 8 publications

References 28 publications

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

Thermally Induced Structural Evolution of Palladium‐Ceria Catalysts. Implication for CO Oxidation

The water gas shift reaction over Pt–CeO2 nanoparticles confined within mesoporous SBA-16

Mesoporous Silica-Supported Nanostructured PdO/CeO2 Catalysts for Low-Temperature Methane Oxidation

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Resources

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The water gas shift reaction over Pt–CeO₂ nanoparticles confined within mesoporous SBA-16

Mesoporous Silica-Supported Nanostructured PdO/CeO₂ Catalysts for Low-Temperature Methane Oxidation