Adsorption-desorption kinetics of NO on a Pd surface with thermal desorption spectroscopy and molecular beam relaxation spectrometry

The adsorption/absorption of hydrogen and the adsorption of carbon monoxide by niobium foils, at room temperature, was studied using thermal desorption spectroscopy. Two hydrogen desorption peaks were observed with a maximum at 404 and 471 K. The first hydrogen desorption peak is regarded as hydrogen desorbing from surface sites while the second peak, which represents desorption from surface sites stronger bound to the surface, also has a component—due to its tailing to higher temperatures—of hydrogen diffusing from subsurface sites. Carbon monoxide adsorption was used to determine the number of surface sites, since it does not penetrate below the surface. Two carbon monoxide desorption peaks are observed in these experiments: at 425 and 608 K. The first peak is regarded as the adsorption of molecular carbon monoxide, and the second, as carbon monoxide dissociated on the niobium surface. The crystallographic orientation of the foils was determined by x-ray diffraction and showed a preferential (110) orientation of the untreated foil due to the effect of cold rolling. This preferential orientation decreased after hydrogen/heat treatment, appearing strong also in the (200) and (211) orientations. This change in texture of the foils is mainly due to the effect of heat treatment and not to hydrogen adsorption/desorption cycling. The kinetics of hydrogen and CO desorption is compared with that of Pd and Pd alloys.

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The Kinetics of Hydrogen Desorption From Zirconium Hydride

Volume 1: Plant Operations, Maintenance, Engineering, Modifications, Life Cycle and Balance of Plant; Nuclear Fuel and Materials; Radiation Protection and Nuclear Technology Applications ◽

10.1115/icone21-15869 ◽

2013 ◽

Author(s):

Mingwang Ma ◽

Ruiyun Wan ◽

Yuan Wang ◽

Yanlin Cheng ◽

Li Liang ◽

...

Keyword(s):

Thermal Desorption ◽

Thermal Desorption Spectroscopy ◽

Hydrogen Desorption ◽

Pressure Effects ◽

Zirconium Hydride ◽

Desorption Kinetics ◽

Desorption Process ◽

Exponential Factor ◽

Predict Weight Loss ◽

Kinetics Of

Thermal desorption spectroscopy (TDS) was used to study the thermal desorption kinetics of zirconium hydride films, which were deposited on molybdenum substrates and thermally charged with gas phase hydrogen. The observed desorption peaks were attributed to phase transforming steps. The activation energy and pre-exponential factor for desorption kinetics was estimated as 116 kJ/mol and 8762 s−1 according to Kissinger relation, respectively. A simulation of TDS spectra was made, which showed that the desorption process followed a first order kinetics. The kinetic parameters were then utilized to predict weight loss behavior at a temperature profile. Pressure effects that can potentially reduce the desorption rate were discussed.

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The Role of Cr in H Desorption Kinetics in Rapidly Solidified Al

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.264 ◽

2014 ◽

Vol 783-786 ◽

pp. 264-269 ◽

Cited By ~ 3

Author(s):

Iya I. Tashlykova-Bushkevich ◽

Keitaro Horikawa ◽

Goroh Itoh

Keyword(s):

High Temperature ◽

Thermal Desorption ◽

High Purity ◽

Thermal Desorption Spectroscopy ◽

Secondary Phase ◽

Hydrogen Desorption ◽

Oxide Surface ◽

Desorption Kinetics ◽

Hydrogen Trapping ◽

Rapidly Solidified

Hydrogen desorption kinetics for rapidly solidified high purity Al and Al-Cr alloy foils containing 1.0, 1.5 and 3.0 at % Cr were investigated by means of thermal desorption analysis (TDA) at a heating rate of 3.3°C/min. For the first time, it was found that oxide inclusions of Al2O3 are dominant high-temperature hydrogen traps compared with pores and secondary phase precipitates resulted in rapid solidification of Al and its alloys. The correspondent high-temperature evolution rate peak was identified to be positioned at 600°C for high purity Al and shifted to 630°C for Al-Cr alloys. Amount of hydrogen trapped by dislocations increases in the alloys depending on Cr content. Microstructural hydrogen trapping behaviour in low-and intermediate temperature regions observed here was in coincidence with previous data obtained for RS materials using thermal desorption spectroscopy (TDS). The present results on hydrogen thermal desorption evolution indicate that the effect of oxide surface layers becomes remarkable in TDA measurements and show advantages in combinations of both desorption analysis methods to investigate hydrogen desorption kinetics in materials.

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A molecular beam study of desorption kinetics of GeO from Ge(111) surfaces

Surface Science ◽

10.1016/0039-6028(93)90960-r ◽

1993 ◽

Vol 283 (1-3) ◽

pp. 64-69 ◽

Cited By ~ 5

Author(s):

Kouichi Sugiyama ◽

Yoshiyuki Igari ◽

Isao Kusunoki

Keyword(s):

Molecular Beam ◽

Desorption Kinetics ◽

Kinetics Of

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MODELING ADSORPTION/DESORPTION KINETICS OF PESTICIDES IN A SOIL SUSPENSION

Soil Science ◽

10.1097/00010694-198810000-00002 ◽

1988 ◽

Vol 146 (4) ◽

pp. 221-231 ◽

Cited By ~ 38

Author(s):

J. J. T. I. BOESTEN ◽

L. J. T. VAN DER PAS

Keyword(s):

Desorption Kinetics ◽

Soil Suspension ◽

Adsorption Desorption ◽

Kinetics Of

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Adsorption/Desorption Kinetics of Zn in Soils: Influence of Phosphate

Molecular Environmental Soil Science at the Interfaces in the Earth’s Critical Zone ◽

10.1007/978-3-642-05297-2_27 ◽

2010 ◽

pp. 88-90 ◽

Cited By ~ 1

Author(s):

H. Magdi Selim ◽

Keli Zhao ◽

Lixia Liao ◽

Jianming Xu

Keyword(s):

Desorption Kinetics ◽

Adsorption Desorption ◽

Kinetics Of

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Adsorption–desorption kinetics of silica coated on textile fabrics by the sol–gel process

Journal of Coatings Technology and Research ◽

10.1007/s11998-019-00281-8 ◽

2019 ◽

Vol 17 (2) ◽

pp. 371-380 ◽

Cited By ~ 1

Author(s):

Mohamed El messoudi ◽

Aicha Boukhriss ◽

Omar Cherkaoui ◽

M’hammed El kouali ◽

Said Gmouh

Keyword(s):

Sol Gel ◽

Desorption Kinetics ◽

Textile Fabrics ◽

Sol Gel Process ◽

Adsorption Desorption ◽

Kinetics Of

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Chloroform desorption from poly(lactic acid) nanocomposites: a thermal desorption spectroscopy study

Pure and Applied Chemistry ◽

10.1515/pac-2018-1216 ◽

2020 ◽

Vol 92 (3) ◽

pp. 391-398 ◽

Cited By ~ 1

Author(s):

Riccardo Checchetto ◽

Daniele Rigotti ◽

Alessandro Pegoretti ◽

Antonio Miotello

Keyword(s):

Lactic Acid ◽

Thermal Desorption ◽

Thermal Desorption Spectroscopy ◽

Zero Order ◽

Poly Lactic Acid ◽

Desorption Kinetics ◽

Residual Solvent ◽

Medical Materials ◽

Solvent Molecules ◽

Second Peak

AbstractBiopolymer nanocomposites were prepared by solvent casting dispersing lauryl-functionalized cellulose nano-fibrils (CNF) in a poly(lactic acid) matrix (PLA). The release of residual chloroform (CHCl3) solvent molecules was studied by Thermal Desorption Spectroscopy (TDS) analysis. TDS spectra of the PLA matrix show a single desorption peak at TP = 393 K with FWHM ~10 K, compatible with a zero-order desorption kinetics. This narrow TDS peak was accurately reproduced assuming that: (i) the rate limiting step is given by the CHCl3 de-trapping from sites in the PLA matrix where residual solvent molecules form small aggregates and (ii) the activation energy for desorption linearly decreases from 1.19 eV for saturated traps to 1.11 eV when the traps occupancy by solvent molecules approaches zero. The balance energy term ϵD = −0.08 eV is due to the attractive interactions between trapped CHCl3 molecules. Adding CNF particles to the PLA matrix the zero-order peak shifts to lower temperatures and a second peak with FWHM ~60 K appears at higher temperatures. This second peak is compatible with a first-order desorption kinetics and is attributed to the release of dispersed CHCl3 molecules from trapping sites in PLA-CNF interface region. The obtained information are of interest for applications in food and electronic packaging and for the development of medical materials.

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