Reaction between NiO and Al2O3 in NiO/γ-Al2O3 catalysts probed by positronium atom

Li, C.Y.; Zhang, Hongjun; Chen, Z.Q.

doi:10.1016/j.apsusc.2012.11.037

Cited by 13 publications

(5 citation statements)

References 30 publications

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“…Impregnation of γ-Al 2 O 3 with Ni salts followed by calcination results in the formation of a NiAl 2 O 4 -like surface layer which is hardly reducible, forming, upon reduction, very small Ni metal clusters [69] which are very selective for CO 2 methanation [52,70], as evident from Figure 3. Instead, even at a high Ni loading, the formation of bulk NiAl 2 O 4 does not occur until at least 873 K, given how the reaction between NiO and γ-Al 2 O 3 is still slow and incomplete even at 1273 K [71]. However, the surface spinel layer stabilizes the Ni/γ-Al 2 O 3 catalysts up to high temperatures [72], preventing bulk transformation and loss of surface area.…”

Section: Ni/al 2 O 3 Catalystsmentioning

confidence: 99%

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

et al. 2023

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A detailed critical analysis of the scientific literature data concerning catalysts for CO2 methanation based on nickel supported over oxides was performed. According to the obtained information, it seems that an ionic support is necessary to allow a good nickel dispersion to produce very small nickel metal particles. Such small metal particles result in being very active toward methanation, limiting the production of carbonaceous materials. The use of support and/or surface additives gives rise to medium surface basicity, allowing medium-strong adsorption of CO2, and it is also advisable to increase the reaction rate. A medium nickel loading would allow the free support geometric surface to be covered densely by small nickel metal particles without the production of larger Ni crystals. It is also advisable to work at temperatures where Ni(CO)4 formation is not possible (e.g., >573 K). The promising properties of systems based on doped Ni/Al2O3, doped with basic and re-active oxides such as MnOx or/and CeO2, and those based on Ni/CeO2 were underlined.

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Section: Ni/al 2 O 3 Catalystsmentioning

confidence: 99%

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

et al. 2023

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“…It has been shown that nickel oxide nanoparticles create large compulsory fields at low temperatures due to the anisotropy of the surface and ring transitions due to the non-coupling of the boundary transformation between the antiferromagnetic nucleus and the irregular magnetic fields. The magnetic behavior of nickel oxide particles is very complex and is strongly influenced by temperature, nucleus particles size, surface, and boundary [110][111][112][113][114].…”

Section: Synthesis Of Nickel Oxide Nanostructures For the Manufacture Of Nanoelectronic Devicesmentioning

confidence: 99%

Application of Carbon Nanotubes(CNT) on The Computer Science and Electrical Engineering:A Review

Moghaddam

Maraki

Rajaei³

2020

IJRES

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In recent years, dimensions and sizes of components and parts in the computer and electronic industries have been steadily reducing, as they are now considered very tiny tools and there is always a need to store and process information stronger. Nanotubes have poor magnetic properties. If nanotubes are covered by ferromagnetic nanoparticles, their magnetic properties can be improved and they can be used in the manufacture of nanoelectronic devices in the computer and electronic industries. In addition to reviewing the structure and properties of materials made using different nanomaterials for use in the computer and electronic industries, the present paper aimed to study different applications of nanomaterials, especially carbon nanotubes, in the manufacture of electronic devices. The present study showed that the corporation of nanomaterials into electronic devices is a promising approach for future applications which can revolutionize the computer industry.

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“…15,16 In the NiAl 2 O 4 structure, the cation arrangement is typical of a partially inverse spinel (Ni 1−z Al z )[Ni z Al 2−z ]O 4 , in which Ni 2+ and Al 3+ are randomly located in both tetrahedral and octahedral positions, respectively. NiAl 2 O 4 pigments have been prepared by various routes such as sol−gel, 17,18 solid-state reaction, 19 microwave, 20,21 sonochemical, 22 Pechini method, 23 thermal decomposition of polynuclear malate complexes, 24 mechanochemical synthesis, 25 and combustion route. 26,27 However, it is still difficult to prepare the stoichiometric NiAl 2 O 4 because of the persistent NiO impurity even if the Ni/Al 1:2 molar ratio is well controlled.…”

Section: Introductionmentioning

confidence: 99%

“…Assuming A 2+ and B 3+ cations, there are two ideal crystallographic structures: the first one is the direct spinel, in which the tetrahedral sites are occupied by the A 2+ cation and the octahedral sites by the B 3+ cation; the second one is the inverse spinel, in which all tetrahedral sites are occupied by the B 3+ cation, while A 2+ and B 3+ cations share in equivalent proportion the octahedral sites. , In the NiAl 2 O 4 structure, the cation arrangement is typical of a partially inverse spinel (Ni 1– z Al z )[Ni z Al 2– z ]O 4 , in which Ni 2+ and Al 3+ are randomly located in both tetrahedral and octahedral positions, respectively. NiAl 2 O 4 pigments have been prepared by various routes such as sol–gel, , solid-state reaction, microwave, , sonochemical, Pechini method, thermal decomposition of polynuclear malate complexes, mechanochemical synthesis, and combustion route. , …”

Section: Introductionmentioning

confidence: 99%

Cyan Ni_1–xAl_2+2x/3□_x/3O₄ Single-Phase Pigment Synthesis and Modification for Electrophoretic Ink Formulation

et al. 2020

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Cyan Ni 1– x Al 2+2 x /3 O 4 single-phase pigments with various Ni/Al atomic ratios (from 1:2 down to 1:4) have been prepared by a sol–gel route (Pechini) followed by postannealing treatments. Nickel aluminates crystallize in the well-known spinel structure ( Fd 3 m space group), where metals are located at two different Wyckoff positions: 16d (octahedron) and 8a (tetrahedron). Based on X-ray diffraction (XRD) Rietveld refinements, Ni 2+ cations are shown to be partially located in both tetrahedral and octahedral sites and, in addition, cationic vacancies occupy the Oh environment. In the pure-phase series, Ni/Al = 0.35, 0.40, 0.45, as the Al content increases, the Ni 2+ rate in the Td site decreases for Ni/Al = 0.45, thus altering the cyan color; within this series, the most saturated cyan coloration is reached for the highest Al concentration. Inorganic pigment drawbacks are their high density and hydrophilic surface, which induce sedimentation and aggregation in nonpolar media used in electrophoretic inks. Hybrid core–shell particle pigments have been synthesized from cyan pigments using nitroxide-mediated radical polymerization (NMRP) with methyl methacrylate monomer in Isopar G, leading to a dispersion of electrically charged hybrids in apolar media. Surface functionalization of the pigments by n -octyltrimethoxysilane (OTS) and n -dodecyltrimethoxysilane (DTS) modifiers has been compared. The inorganic pigments are successfully encapsulated by organic shells to allow a strong decrease in their density. Cyan inks, adequate for their use in e-book readers or other electrophoretic displays, taking further advantage of the high contrast ratio and reflectivity of inorganic pigments in regard to organic dyes, have been stabilized.

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Reaction between NiO and Al2O3 in NiO/γ-Al2O3 catalysts probed by positronium atom

Cited by 13 publications

References 30 publications

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

Application of Carbon Nanotubes(CNT) on The Computer Science and Electrical Engineering:A Review

Cyan Ni_1–xAl_2+2x/3□_x/3O₄ Single-Phase Pigment Synthesis and Modification for Electrophoretic Ink Formulation

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Reaction between NiO and Al2O3 in NiO/γ-Al2O3 catalysts probed by positronium atom

Cited by 13 publications

References 30 publications

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

Looking for an Optimal Composition of Nickel-Based Catalysts for CO2 Methanation

Application of Carbon Nanotubes(CNT) on The Computer Science and Electrical Engineering:A Review

Cyan Ni1–xAl2+2x/3□x/3O4 Single-Phase Pigment Synthesis and Modification for Electrophoretic Ink Formulation

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Product

Resources

About

Cyan Ni_1–xAl_2+2x/3□_x/3O₄ Single-Phase Pigment Synthesis and Modification for Electrophoretic Ink Formulation