Pt Nanoparticles Embedded in Colloidal Crystal Template Derived 3D Ordered Macroporous Ce0.6Zr0.3Y0.1O2: Highly Efficient Catalysts for Methane Combustion

Arandiyan, Hamidreza; Dai, Hongxing; Ji, Kemeng; Sun, Hongyu; Li, Junhua

doi:10.1021/cs501773h

Cited by 117 publications

(77 citation statements)

References 64 publications

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“…The H 2 ‐TPR profile of mesoporous Ce 0.8 Zr 0.2 O 2 solid solutions also presents two reduction peaks centered at 450 and 650 °C, much lower than those of mesoporous CeO 2 , which is mainly due to the increased mobility of lattice oxygen from bulk to surface after introduction of Zr 4+ into CeO 2 lattice . Furthermore, the supported Pt nanoparticles can dramatically enhance the reduction capacity of the surface oxygen in CeO 2 or Ce x Zr 1− x O 2 solid solutions 10c. Therefore, the mesoporous Pt/Ce 0.8 Zr 0.2 O 2 catalyst displays reduction peaks at much lower temperatures of 350 and 600 °C and shows much higher H 2 consumption than the parent mesoporous Ce 0.8 Zr 0.2 O 2 10c.…”

Section: Resultsmentioning

confidence: 96%

“…It should be mentioned that, in comparison with pure mesoporous CeO 2 and ZrO 2 with relatively sharp diffraction peaks (Figure A, e and a), the samples of mesoporous Ce 0.8 Zr 0.2 O 2 , Ce 0.5 Zr 0.5 O 2 , and Ce 0.2 Zr 0.8 O 2 exhibit broadened peaks (Figure A, d–b), implying the formation of smaller Ce x Zr 1− x O 2 crystallites in the framework. This result clearly indicates that the cohydrolysis of cerium with zirconium precursors and their co‐assembly with block copolymers tend to form Ce x Zr 1− x O 2 crystallites at nanoscale with enhanced thermal stability 10a. Ce x Zr 1− x O 2 solid solutions have three stable phases, i.e., monoclinic, tetragonal, and cubic, but it is difficult to identify their crystallographic structure simply according to the broadened diffraction peaks in XRD patterns.…”

Section: Resultsmentioning

confidence: 99%

“…H 2 temperature‐programmed reduction (TPR) measurement was conducted to assess the intrinsic reducibility of the obtained samples, and the hydrogen consumption profiles as a function of temperature were displayed in Figure S11 (Supporting Information). The pristine mesoporous CeO 2 exhibits two reduction peaks at around 550 and 850 °C, ascribed to the surface and bulk reduction of Ce 4+ , respectively 10a. The H 2 ‐TPR profile of mesoporous Ce 0.8 Zr 0.2 O 2 solid solutions also presents two reduction peaks centered at 450 and 650 °C, much lower than those of mesoporous CeO 2 , which is mainly due to the increased mobility of lattice oxygen from bulk to surface after introduction of Zr 4+ into CeO 2 lattice .…”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, the supported Pt nanoparticles can dramatically enhance the reduction capacity of the surface oxygen in CeO 2 or Ce x Zr 1− x O 2 solid solutions 10c. Therefore, the mesoporous Pt/Ce 0.8 Zr 0.2 O 2 catalyst displays reduction peaks at much lower temperatures of 350 and 600 °C and shows much higher H 2 consumption than the parent mesoporous Ce 0.8 Zr 0.2 O 2 10c. This phenomenon can be attributed to the dissociated H 2 on Pt surfaces and the formed hydrogen spillover onto the vicinity of metal oxide support, which can promote the reduction of metal oxide support at low temperature .…”

Section: Resultsmentioning

confidence: 99%

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Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Yang

Cheng

et al. 2019

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Active and stable catalysts are highly desired for converting harmful substances (e.g., CO, NOx) in exhaust gases of vehicles into safe gases at low exhaust temperatures. Here, a solvent evaporation–induced co‐assembly process is employed to design ordered mesoporous CexZr1−xO2 (0 ≤ x ≤ 1) solid solutions by using high‐molecular‐weight poly(ethylene oxide)‐block‐polystyrene as the template. The obtained mesoporous CexZr1−xO2 possesses high surface area (60–100 m2 g−1) and large pore size (12–15 nm), enabling its great capacity in stably immobilizing Pt nanoparticles (4.0 nm) without blocking pore channels. The obtained mesoporous Pt/Ce0.8Zr0.2O2 catalyst exhibits superior CO oxidation activity with a very low T100 value of 130 °C (temperature of 100% CO conversion) and excellent stability due to the rich lattice oxygen vacancies in the Ce0.8Zr0.2O2 framework. The simulated catalytic evaluations of CO oxidation combined with various characterizations reveal that the intrinsic high surface oxygen mobility and well‐interconnected pore structure of the mesoporous Pt/Ce0.8Zr0.2O2 catalyst are responsible for the remarkable catalytic efficiency. Additionally, compared with mesoporous Pt/CexZr1−xO2‐s with small pore size (3.8 nm), ordered mesoporous Pt/CexZr1−xO2 not only facilitates the mass diffusion of reactants and products, but also provides abundant anchoring sites for Pt nanoparticles and numerous exposed catalytically active interfaces for efficient heterogeneous catalysis.

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Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Yang

Cheng

et al. 2019

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“…339,343,344 For example, Arandiyam et al fabricated 3D ordered macro/mesoporous Pt/Ce 0.6 Zr 0.3 Y 0.1 O 2 (CZY) catalysts for methane combustion using PMMA as hard template and pluronic (P123) as surfactant (Figure 24 A,B). 348 The excellent catalytic activity of Pt/CZY was ascribed to an increase in surface area due to its unique macro/mesoporous structure as well as its high concentration of adsorbed oxygen, good low-temperature reducibility, and strong catalyst-support interaction due to composition.…”

Section: Factors Influencing Cbpm Catalystsmentioning

confidence: 99%

A colloidoscope of colloid-based porous materials and their uses

et al. 2016

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Nature evolved a variety of hierarchical structures that produce sophisticated functions. Inspired by these natural materials, colloidal self-assembly provides a convenient way to produce structures from simple building blocks with a variety of complex functions beyond those found in nature. In particular, colloid-based porous materials (CBPM) can be made from a wide variety of materials. The internal structure of CBPM also has several key attributes, namely porosity on a sub-micrometer length scale, interconnectivity of these pores, and a controllable degree of order. The combination of structure and composition allow CBPM to attain properties important for modern applications such as photonic inks, colorimetric sensors, self-cleaning surfaces, water purification systems, or batteries. This review summarizes recent developments in the field of CBPM, including principles for their design, fabrication, and applications, with a particular focus on structural features and materials' properties that enable these applications. We begin with a short introduction to the wide variety of patterns that can be generated by colloidal self-assembly and templating processes. We then discuss different applications of such structures, focusing on optics, wetting, sensing, catalysis, and electrodes. Different fields of applications require different properties, yet the modularity of the assembly process of CBPM provides a high degree of tunability and tailorability in composition and structure. We examine the significance of properties such as structure, composition, and degree of order on the materials' functions and use, as well as trends in and future directions for the development of CBPM.

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Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion

Dai

Kumar

Zhu

et al. 2019

Adv Funct Materials

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Bowtie-shaped NiCo 2 O 4 nanostructures are prepared using a hydrothermal method. Variation of the synthesis parameters, including reaction time, additives, and calcination temperature, allows an understanding of the origin of the bowtie-shaped structure to be developed. Methane oxidation experiments performed using temperature-programed oxidation (TPO) show that the new materials, which do not contain precious metals, have excellent activity for low-temperature methane combustion, with 100% conversion at ≈410 °C (gas hourly space velocity (GHSV): 90 000 mL (STP) g −1 h −1 ). The structure-activity relationships of the bowtie-shaped nanostructures are explored. The relatively low exhaust temperature in NGVs means that the activation of methane, which has the strongest CH bond of any hydrocarbon, is challenging from a chemical perspective. It is not surprising that the quest for effective lowtemperature methane oxidation catalysts has focused mainly on systems involving precious metals, such as platinum and palladium. [11][12][13][14][15] Metal oxidesupported PdO catalysts are generally considered to represent the state of the art for methane combustion catalysts. [16][17][18][19][20] Recent research in this field has focused on improving activity at low temperatures, [21,22] reducing the required loading of metal [23,24] and improving the thermal and hydrothermal stability of PdO catalysts. [25][26][27][28][29][30] Exciting recent advances include the development of core-shell Pd@CeO 2 catalysts with high activity and thermal stability, demonstrating complete conversion to CO 2 below 400 °C (gas hourly space velocity (GHSV) = 200 000 mL g −1 h −1 ). [21] Pd@ZrO 2 /Si-Al 2 O 3 catalysts that are stable in the presence of high concentrations of water vapor have also been proposed recently. [25] NiO@PdO/Al 2 O 3 catalysts that show good activity and stability with only 0.2 wt% Pd loading have been prepared [23] as well as Pd-based bimetallic nanocrystalline catalysts, in which the promotional effects of different transition metals have been examined. [26] Although Pd-based catalysts show excellent activity, the high price and low abundance of palladium are limiting factors to practical application, [31] and both the hydrothermal stability and SO 2 tolerance for these catalysts need to be improved. For this reason, the development of alternative catalysts based on non-noble metals is attractive. [32] These include single metal oxide-based catalysts (CuO, [33] Co 3 O 4 , [34] and MnO 2 [35] ), perovskite, [36,37] spinel, [38,39] and hexaaluminate [40] catalysts. Among these, Co 3 O 4 exhibits good activity for methane combustion attributed to a spinel-type structure with variable Co oxidation states and a high density of oxygen vacancies on the surface. [41] Additionally, the specific exposed facets and morphology of Co 3 O 4 plays an important role in the catalysis. [42,43] Materials with exposed (110) planes show enhanced catalytic activity for methane oxidation compared with those only exposing (100) or (111) face...

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Pt Nanoparticles Embedded in Colloidal Crystal Template Derived 3D Ordered Macroporous Ce_0.6Zr_0.3Y_0.1O₂: Highly Efficient Catalysts for Methane Combustion

Cited by 117 publications

References 64 publications

Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

A colloidoscope of colloid-based porous materials and their uses

Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion

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Pt Nanoparticles Embedded in Colloidal Crystal Template Derived 3D Ordered Macroporous Ce0.6Zr0.3Y0.1O2: Highly Efficient Catalysts for Methane Combustion

Cited by 117 publications

References 64 publications

Large‐Pore Mesoporous CeO2–ZrO2 Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Large‐Pore Mesoporous CeO2–ZrO2 Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

A colloidoscope of colloid-based porous materials and their uses

Bowtie‐Shaped NiCo2O4 Catalysts for Low‐Temperature Methane Combustion

Contact Info

Product

Resources

About

Pt Nanoparticles Embedded in Colloidal Crystal Template Derived 3D Ordered Macroporous Ce_0.6Zr_0.3Y_0.1O₂: Highly Efficient Catalysts for Methane Combustion

Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Large‐Pore Mesoporous CeO₂–ZrO₂ Solid Solutions with In‐Pore Confined Pt Nanoparticles for Enhanced CO Oxidation

Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion