Physicochemical Characterization of Highly Dispersed Platinum and Chromium on Zeolite Beta

Izutsu, Yoshiyuki; Oku, Yuki; Hidaka, Yusuke; Kanaya, Naoki; Nakajima, Yoshiyuki; Fukuroi, Jun; Yoshida, Kaname; Sasaki, Yukichi; Sekine, Yasushi; Matsukata, Masahiko

doi:10.1021/jp500232s

Cited by 12 publications

(5 citation statements)

References 32 publications

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“…The UFF parameters are generated from a set of rules based on element, hybridization and connectivity. Implementations on this forcefield have been rigorously tested, and the results are in agreement with published works [20,21]. In MMs, the potential energy of the UFF is expressed as the sum of the bonded and nonbonded interactions…”

Section: Computational Detailssupporting

confidence: 76%

Shear displacement controlled periodic wrinkles in hexagonal boron nitride sheet

2014

Nanotechnology

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The initiation and geometry pattern of wrinkles in a single-layer hexagonal boron nitride sheet induced by in-plane shear displacement are studied. The periodic wrinkles in the central region are parallel to each other with an angle of approximate 50° to the fix edges, and the longitudinal shape of the wrinkle matches the sinusoidal mode shape well. The wrinkle wavelength decreases with an increase in shear loading, while the amplitude is found to initially increase and then become stable. The dependence of the wrinkle geometry on chirality and shear direction is further elucidated. This study theoretically provides a powerful way to produce uniform wrinkles in two-dimensional membranes and to tune their properties in devices.

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Section: Computational Detailssupporting

confidence: 76%

Shear displacement controlled periodic wrinkles in hexagonal boron nitride sheet

2014

Nanotechnology

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“…We note that the role of the MFI‐Ns in stabilizing nanoparticles is reminiscent of research practices which use hydroxyls to 1) increase the interaction strength and stabilize copper nanoclusters on α‐aluminum oxide, [ 22 ] iron clusters on amorphous aluminum oxide, [ 23 ] and gold clusters on magnesium oxide, [ 24 ] to 2) stabilize metal clusters in the pores of zeolites, [ 25 ] and—recently—to 3) stabilize gold nanoparticles on the surface of MCM‐41 zeolites, [ 26 ] suggesting that these may increase the affinity of other metal adatoms and adparticles to the zeolite terrace in a similar fashion. Hence, we suspect that Q3 sites (Si‐OH groups generated by the termination of the framework connectivity along the b ‐axis of the MFI‐Ns) on the basal planes of MFI‐Ns play a significant role in determining the particle/support interaction and catalytic outcome, as seen elsewhere.…”

Section: Figurementioning

confidence: 99%

Zeolite Nanosheets Stabilize Catalyst Particles to Promote the Growth of Thermodynamically Unfavorable, Small‐Diameter Carbon Nanotubes

Carpena‐Núñez

Rao

Kim

et al. 2020

Small

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The integration of single wall carbon nanotubes (single wall CNTs or SWCNTs) in large-scale applications is still halted by the lack of control and by the limited understanding of factors influencing growth. [1] In particular, the synthesis of sub-nm semiconducting and metallic SWCNTs has proven to be difficult due to problems associated with catalyst nanoparticle coarsening and the slow kinetics at the lower temperatures and pressures required for their growth. Sub-nm diameter semiconducting SWCNTs exhibit electrical bandgaps greater than 1 eV while their metallic counterparts exhibit bandgaps <0.14 eV, [2] making them ideal for electronic devices. Although significant progress has been made in the past decade toward achieving controlled growth of SWCNTs, [3] factors such as particle/support interactions, particle/tube epitaxy, and kinetics mainly result in the A challenge in the synthesis of single-wall carbon nanotubes (SWCNTs) is the lack of control over the formation and evolution of catalyst nanoparticles and the lack of control over their size or chirality. Here, zeolite MFI nanosheets (MFI-Ns) are used to keep cobalt (Co) nanoparticles stable during prolonged annealing conditions. Environmental transmission electron microscopy (ETEM) shows that the MFI-Ns can influence the size and shape of nanoparticles via particle/ support registry, which leads to the preferential docking of nanoparticles to four or fewer pores and to the regulation of the SWCNT synthesis products. The resulting SWCNT population exhibits a narrow diameter distribution and SWCNTs of nearly all chiral angles, including sub-nm zigzag (ZZ) and near-ZZ tubes. Theoretical simulations reveal that the growth of these unfavorable tubes from unsupported catalysts leads to the rapid encapsulation of catalyst nanoparticles bearing them; their presence in the growth products suggests that the MFI-Ns prevent nanoparticle encapsulation and prologue ZZ and near-ZZ SWCNT growth. These results thus present a path forward for controlling nanoparticle formation and evolution, for achieving size-and shape-selectivity at high temperature, and for controlling SWCNT synthesis.

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“…The abundance of hydroxyl groups at defective sites plays a crucial role in the dispersion of metal NPs, facilitating interactions with active metal species through hydrogen bonding. This interaction serves as an anchoring point, contributing to the active metal uniformly dispersing on zeolite [ 21 , 49 ].…”

Section: Resultsmentioning

confidence: 99%

Enhanced Adsorption of Trace Ethylene on Ag/NZ5 Modified with Ammonia: Hierarchical Structure and Metal Dispersion Effects

Qi,

Yang,

et al. 2024

Molecules

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Trace ethylene poses a significant challenge during the storage and transportation of agricultural products, causing over-ripening, reducing shelf life, and leading to food waste. Zeolite-supported silver adsorbents show promise for efficiently removing trace ethylene. Herein, hierarchical Ag/NZ5(X) adsorbents were prepared via different ammonia modifications, which featured enhanced ethylene adsorption ability. Ag/NZ5(2.5) exhibited the largest capacity and achieved near-complete removal at room temperature with prolonged efficacy. Characterization results indicated that the ammonia modification led to the formation of a hierarchical structure in the zeolite framework, reducing diffusion resistance and increasing the accessibility of the active sites. Additionally, desilication effects increased the defectiveness, generating a stronger metal–support interaction and resulting in a higher metal dispersion rate. These findings provide valuable insights into the development of efficient adsorbents for removing trace ethylene, thereby reducing food waste and extending the shelf life of agricultural products.

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Physicochemical Characterization of Highly Dispersed Platinum and Chromium on Zeolite Beta

Cited by 12 publications

References 32 publications

Shear displacement controlled periodic wrinkles in hexagonal boron nitride sheet

Shear displacement controlled periodic wrinkles in hexagonal boron nitride sheet

Zeolite Nanosheets Stabilize Catalyst Particles to Promote the Growth of Thermodynamically Unfavorable, Small‐Diameter Carbon Nanotubes

Enhanced Adsorption of Trace Ethylene on Ag/NZ5 Modified with Ammonia: Hierarchical Structure and Metal Dispersion Effects

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