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Hydrogen adsorption on two catalysts for the ortho- to parahydrogen conversion : Cr-doped silica and ferric oxide gel

Hartl, Monika LU ; Gillis, Robert Chad; Daemen, Luke; Olds, Daniel P; Page, Katherine; Carlson, Stefan LU ; Cheng, Yongqiang; Hügle, Thomas; Iverson, Erik B and Ramirez-Cuesta, A J, et al. (2016) In Physical Chemistry Chemical Physics 18(26). p.17281-17293
Abstract

Molecular hydrogen exists in two spin-rotation coupled states: parahydrogen and orthohydrogen. Due to the variation of energy with rotational level, the occupation of ortho- and parahydrogen states is temperature dependent, with parahydrogen being the dominant species at low temperatures. The equilibrium at 20 K (99.8% parahydrogen) can be reached by natural conversion only after a lengthy process. With the use of a suitable catalyst, this process can be shortened significantly. Two types of commercial catalysts currently being used for ortho- to parahydrogen conversion are: iron(iii) oxide (Fe2O3, IONEX®), and chromium(ii) oxide doped silica catalyst (CrO·SiO2, OXISORB®). We investigate the interaction of ortho- and parahydrogen with... (More)

Molecular hydrogen exists in two spin-rotation coupled states: parahydrogen and orthohydrogen. Due to the variation of energy with rotational level, the occupation of ortho- and parahydrogen states is temperature dependent, with parahydrogen being the dominant species at low temperatures. The equilibrium at 20 K (99.8% parahydrogen) can be reached by natural conversion only after a lengthy process. With the use of a suitable catalyst, this process can be shortened significantly. Two types of commercial catalysts currently being used for ortho- to parahydrogen conversion are: iron(iii) oxide (Fe2O3, IONEX®), and chromium(ii) oxide doped silica catalyst (CrO·SiO2, OXISORB®). We investigate the interaction of ortho- and parahydrogen with the surfaces of these ortho-para conversion catalysts using neutron vibrational spectroscopy. The catalytic surfaces have been characterized using X-ray absorption fine structure (XAFS) and X-ray/neutron pair distribution function measurements.

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publication status
published
subject
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Physical Chemistry Chemical Physics
volume
18
issue
26
pages
13 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:84976877606
  • wos:000379482100018
ISSN
1463-9084
DOI
10.1039/c6cp01154c
language
English
LU publication?
yes
id
d7842671-8cec-40e4-9573-bb6e9d8e9f0f
date added to LUP
2016-05-09 13:23:21
date last changed
2017-09-17 09:13:04
@article{d7842671-8cec-40e4-9573-bb6e9d8e9f0f,
  abstract     = {<p>Molecular hydrogen exists in two spin-rotation coupled states: parahydrogen and orthohydrogen. Due to the variation of energy with rotational level, the occupation of ortho- and parahydrogen states is temperature dependent, with parahydrogen being the dominant species at low temperatures. The equilibrium at 20 K (99.8% parahydrogen) can be reached by natural conversion only after a lengthy process. With the use of a suitable catalyst, this process can be shortened significantly. Two types of commercial catalysts currently being used for ortho- to parahydrogen conversion are: iron(iii) oxide (Fe2O3, IONEX®), and chromium(ii) oxide doped silica catalyst (CrO·SiO2, OXISORB®). We investigate the interaction of ortho- and parahydrogen with the surfaces of these ortho-para conversion catalysts using neutron vibrational spectroscopy. The catalytic surfaces have been characterized using X-ray absorption fine structure (XAFS) and X-ray/neutron pair distribution function measurements.</p>},
  author       = {Hartl, Monika and Gillis, Robert Chad and Daemen, Luke and Olds, Daniel P and Page, Katherine and Carlson, Stefan and Cheng, Yongqiang and Hügle, Thomas and Iverson, Erik B and Ramirez-Cuesta, A J and Lee, Yong Joong and Muhrer, Günter},
  issn         = {1463-9084},
  language     = {eng},
  month        = {05},
  number       = {26},
  pages        = {17281--17293},
  publisher    = {Royal Society of Chemistry},
  series       = {Physical Chemistry Chemical Physics},
  title        = {Hydrogen adsorption on two catalysts for the ortho- to parahydrogen conversion : Cr-doped silica and ferric oxide gel},
  url          = {http://dx.doi.org/10.1039/c6cp01154c},
  volume       = {18},
  year         = {2016},
}