Improved hydrogen adsorption of ZnO doped multi-walled carbon nanotubes

ABSTRACTMultiwalled carbon nanotubes (MWNTs) were continuously synthesized by hot wire chemical vapor deposition (HWCVD) using a methane source catalyzed by metal-organic ferrocene. The microstructure of the MWNTs and the catalyst particles were subsequently characterized with transmission electron microscopy which identified three different phases, i.e., bcc α-Fe, fcc γ-Fe and orthorhombic Fe3C. The hydrogen storage capacity of MWNTs was determined with temperature-programmed desorption (TPD) technique. Hydrogen adsorption at near ambient conditions was observed only in as-synthesized MWNTs containing iron particles and was dramatically increased after hydrogen reducing treatment. Possible adsorption mechanism was also discussed.

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Synthesis of multi-walled carbon nanotubes in high yield using Mm based AB2alloy hydride catalysts and the effect of purification on their hydrogen adsorption properties

Nanotechnology ◽

10.1088/0957-4484/16/4/031 ◽

2005 ◽

Vol 16 (4) ◽

pp. 518-524 ◽

Cited By ~ 25

Author(s):

M M Shaijumon ◽

N Rajalakshmi ◽

Hojin Ryu ◽

S Ramaprabhu

Keyword(s):

Carbon Nanotubes ◽

Hydrogen Adsorption ◽

Adsorption Properties ◽

High Yield ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Determination of the Isosteric Heat of Adsorption of Hydrogen on the Multi-Walled Carbon Nanotubes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.512-515.1484 ◽

2012 ◽

Vol 512-515 ◽

pp. 1484-1491 ◽

Cited By ~ 1

Author(s):

Qing Rong Zheng ◽

Shuai Gao ◽

Chen Jie

Keyword(s):

Carbon Nanotubes ◽

Hydrogen Adsorption ◽

Isosteric Heat ◽

Heat Of Adsorption ◽

Step Method ◽

Surface Loading ◽

Isosteric Heat Of Adsorption ◽

Hydrogen Molecules ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

The isosteric heat of adsorption was used to study the interaction between hydrogen molecules and the Multi-Walled Carbon Nanotubes (MWCNTs). Characterizations of the MWCNTs sample were carried out based on the N2 adsorption isotherm at 77 K and the images from TEM and HRTEM. Step by step method was used to volumetrically measure hydrogen adsorption isotherms at equilibrium temperature-pressures from 123-310 K and 0-12.3 MPa. Isosteric heats of adsorption at seven excess adsorption amounts and that at zero surface loading were respectively determined by the slopes of the adsorption isosteres and the plot of the temperature dependence of the Henry’s constants. Results show that the limit of the isosteric heat of adsorption at zero surface loading is about and the mean under the experimental condition is about . The values are in the same grade as those of hydrogen on the activated coconut charcoal but smaller than those of hydrogen on the graphitized carbon black P33, the activated carbon AX-21 and the Single-Walled Carbon Nanotubes (SWCNTs). Conclusions are drawn that relatively lower adsorption amounts and the isosteric heat of hydrogen adsorption on the MWCNTs could be ascribed to the small specific surface area and the large mesopores.

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Studies of Multi-walled Carbon Nanotubes and Their Capabilities of Hydrogen Adsorption

Nanostructured Materials for Energy Related Applications - Environmental Chemistry for a Sustainable World ◽

10.1007/978-3-030-04500-5_6 ◽

2019 ◽

pp. 145-162

Author(s):

Edgar Mosquera ◽

Mauricio Morel ◽

Donovan E. Diaz-Droguett ◽

Nicolás Carvajal ◽

Rocío Tamayo ◽

...

Keyword(s):

Carbon Nanotubes ◽

Hydrogen Adsorption ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Hydrogen Adsorption and Equilibrium Models on Multi-Walled Carbon Nanotubes at Moderate Temperatures and Pressures

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1691 ◽

2008 ◽

Vol 6 (1) ◽

Cited By ~ 2

Author(s):

Mehrdad Gholamhosseiny ◽

Shohreh Fatemi ◽

Maryam Rasoolzadeh

Keyword(s):

Carbon Nanotubes ◽

Hydrogen Adsorption ◽

Isosteric Heat ◽

Isotherm Models ◽

Adsorbed Hydrogen ◽

Operational Conditions ◽

Heats Of Adsorption ◽

Different Temperatures ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Hydrogen adsorption was studied on treated multi-walled carbon nanotubes (MWCNTs). The amounts of hydrogen adsorbed on this adsorbent were measured at three temperatures (298, 273 and 263 K) and various pressures from 10 up to 70 bar in a volumetric adsorption apparatus. In the studied ranges of operational conditions, the maximum adsorbed hydrogen was determined as 0.28 wt%, at the lowest temperature of 263 K and the highest pressure of 70 bar, by the static measurements at the equilibrium condition. The experimental adsorption isotherms were obtained at different temperatures and they were correlated by Dubinin-Astokhov (DA), Sips, Freundlich and Dubinin-Rudushkevich (DR) equations. The isosteric heat of adsorption was determined from both experimental isosters and isotherm models as a function of the adsorbed amount. The isosteric heats of adsorption revealed that MWCNTs would be an energetically heterogeneous surface. Sips model showed a better fitting of the experimental and theoretical isosteric heats of adsorption values and indicated a weak temperature dependency of the isosteric heat.

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