<i>In situ</i>ETEM synthesis of NiGa alloy nanoparticles from nitrate salt solution

Damsgaard, Christian Danvad; Duchstein, Linus Daniel Leonhard; Sharafutdinov, Irek; Nielsen, Morten Godtfred; Chorkendorff, Ib; Wagner, Jakob Birkedal

doi:10.1093/jmicro/dfu025

Cited by 6 publications

(3 citation statements)

References 14 publications

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“…Environmental transmission electron microscopy (ETEM), as a local in situ analysis technique, provides the opportunity to study the nanoparticles under reactive atmosphere, in a pressure range that is similar to that of NAP‐XPS . For example, it was used to follow the formation of NiGa alloy nanoparticles and there deactivation during catalytic methanol formation . In situ imaging with simultaneous spectroscopy during reactions in the ETEM is feasible, providing direct evidence of structural and elemental changes within the bimetallic nanoparticles during reactions .…”

Section: Introductionmentioning

confidence: 99%

“…[19], [20] For example, it was used to follow the formation of NiGa alloy nanoparticles and there deactivation during catalytic methanol formation. [21,22] In situ imaging with simultaneous spectroscopy during reactions in the ETEM is feasible providing direct evidence of structural and elemental changes within the bimetallic nanoparticles during reactions. [23], [24] However, a general limitation of this technique is its local character: only a few nanoparticles may be analyzed in-depth.…”

Section: Introductionmentioning

confidence: 99%

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Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

Carenco

Bonifacio

Yang

2018

Chemistry A European J

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Bimetallic nanoparticles are widely studied, for example in catalysis. However, possible restructuring in the environment of use, such as segregation or alloying, may occur. Taken individually, state-of-the-art analytical tools fail to give an overall picture of these transformations. This study combines an ensemble analysis (near-ambient-pressure X-ray photoelectron spectroscopy) with a local analysis (environmental transmission electron microscopy) to provide an in situ description of the restructuring of core-shell nickel-cobalt nanoparticles exposed to cycles of reduction and oxidation. It reveals a partial surface alloying accompanied by fragmentation of the shell into smaller clusters, which is not reversible. Beyond this case study, the methodology proposed here should be applicable in a broad range of studies dealing with the reactivity of mono- or bi-metallic metal nanoparticles.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

Carenco

Bonifacio

Yang

2018

Chemistry A European J

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“…Among them, the environmental transmission electron microscope (ETEM), which introduces a gas or liquid atmosphere around the sample chamber of a TEM, is a valuable technique to investigate the gas‐solid or liquid‐solid interactions at a nanometer scale. The ETEM can also be used to perform in situ synthesis of nanomaterials to obtain the knowledge of the time‐ and temperature‐resolved dynamic and kinetic mechanisms at near‐atomic resolution . For instance, Hitachi has developed a 300 kV high‐resolution H‐9500 TEM with gas injection/heating capability by using a gas injection/specimen heating holder.…”

Section: Introductionmentioning

confidence: 99%

CFD modelling of gas flow characteristics for the gas‐heating holder in environmental transmission electron microscope

Zhao

Wang

et al. 2018

Can J Chem Eng

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The environmental transmission electron microscope (ETEM) is an effective tool for understanding the behaviour of materials at an atomic level. In the present work, we have characterized the dynamics of gas flow in ETEM using computational fluid dynamic (CFD) simulations. The gas pressure drop, pressure distribution, and gas flow of different inlet pressures for a gas chamber are investigated. Based on the detailed CFD simulations, the hydrodynamics for the gas-heating holder are carried out. Also, an attempt has been made to optimize the structure, and it is proposed that the triangle shaped inlet tube is more suitable. The results presented are useful for understanding the dynamics of gas flow in a gas chamber and provide a basis for further structure optimizations.

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Novel Ni‐Ga alloy based catalyst for converting CO₂ to methanol

Nguyen

Dang²,

Nguyen³

et al. 2017

Can J Chem Eng

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Novel and advanced catalysts based on Ni‐Ga alloy were prepared through co‐condensation method with and without evaporation of water solvent for converting CO2 to methanol. The co‐condensations used Ni(NO3)2 and Ga metal as beginning precursors under alkaline media. Various Ni/Ga molar ratios and temperature of the co‐condensation‐evaporation method were investigated in order to obtain Ni5Ga3 alloy composition as active phase for the catalysts. The results confirmed that the stoichiometry of 5/3 could be reached at the same molar ratio of the beginning precursors, and the suitable temperature of the method was 80 °C for a certain time of 24 h. The Ni‐Ga based catalyst activity and selectivity were also tested in the conversion of CO2 to methanol at atmospheric pressure and 220 °C for different periods of time. The results showed that the catalyst was an excellent candidate for this process compared to other catalysts when exposing good selectivity over 90 % during long periods of time. Many techniques were used including X‐Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X‐Ray Photoelectron Spectroscopy (XPS), Nitrogen Adsorption–Desorption Analysis (BET), and Gas Chromatography (GC) to characterize the catalyst structure and the reaction performance, respectively.

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In situETEM synthesis of NiGa alloy nanoparticles from nitrate salt solution

Cited by 6 publications

References 14 publications

Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

CFD modelling of gas flow characteristics for the gas‐heating holder in environmental transmission electron microscope

Novel Ni‐Ga alloy based catalyst for converting CO₂ to methanol

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In situETEM synthesis of NiGa alloy nanoparticles from nitrate salt solution

Cited by 6 publications

References 14 publications

Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

Ensemble versus Local Restructuring of Core‐shell Nickel–Cobalt Nanoparticles upon Oxidation and Reduction Cycles

CFD modelling of gas flow characteristics for the gas‐heating holder in environmental transmission electron microscope

Novel Ni‐Ga alloy based catalyst for converting CO2 to methanol

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Product

Resources

About

Novel Ni‐Ga alloy based catalyst for converting CO₂ to methanol