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Cation vacant Fe(3-x-y)V(x)□(y)O(4) spinel-type catalysts for the oxidation of methanol to formaldehyde

Massa, Mariano LU ; Häggblad, Robert LU and Andersson, Arne LU (2011) In Topics in Catalysis 54(10-12). p.685-697
Abstract
The potential of Fe-V-oxide catalysts for use in methanol oxidation is explored. Our results show that although FeVO4 is active and selective for formaldehyde formation, it is not completely stable towards volatilization under reaction conditions. Attempts to stabilize Fe-V-oxide were made using titania, alumina and silica supports. However, we observe that although some stabilization is achieved using titania and alumina, the supported catalysts are sensitive to volatilization considering the relatively low content of active oxide. Compared with supported V-oxide, the results show that iron causes stabilization of vanadium decreasing its volatility. Considering the observation that the neat FeVO4 restructures to form a spinel-type phase... (More)
The potential of Fe-V-oxide catalysts for use in methanol oxidation is explored. Our results show that although FeVO4 is active and selective for formaldehyde formation, it is not completely stable towards volatilization under reaction conditions. Attempts to stabilize Fe-V-oxide were made using titania, alumina and silica supports. However, we observe that although some stabilization is achieved using titania and alumina, the supported catalysts are sensitive to volatilization considering the relatively low content of active oxide. Compared with supported V-oxide, the results show that iron causes stabilization of vanadium decreasing its volatility. Considering the observation that the neat FeVO4 restructures to form a spinel-type phase under influence of the catalysis, we prepared a series of cation vacant spinel-type Fe3-x-yVx□yO4 catalysts with various V/Fe ratio and consequent number of cation vacancies □. Opposed to the activity, which is rather constant irrespectively of the vanadium content, the selectivity to formaldehyde passes through a maximum of about 90% for Fe/V = 14. A spinel-type phase with the composition Fe2.62V0.19□0.20O4 was prepared and subsequently preoxidized to different degree. It is observed that the spinel-type structure is stable and that the oxidation of vanadium and iron is balanced by an increasing number of cation vacancies. Moreover, irrespectively of the original degree of preoxidation, it is found that in methanol oxidation a steady state is reached where all samples are equally active and selective and have the same composition both in the bulk and at the surface. The results clearly demonstrate that the spinel-type catalysts are phase-stable, nonvolatile and flexible in that the cations can change oxidation state retaining the same basic structure type and Fe/V ratio. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Oxidation, Methanol, Formaldehyde, Fe-V-oxide catalysts, Cation vacant spinel-type Fe3-x-yVx□yO4 catalysts, Volatility, XANES, XPS, XRD
in
Topics in Catalysis
volume
54
issue
10-12
pages
685 - 697
publisher
Kluwer
external identifiers
  • wos:000292003900011
  • scopus:80051595137
ISSN
1572-9028
DOI
10.1007/s11244-011-9690-1
language
English
LU publication?
yes
id
43a5e530-64bc-46e6-8dfa-30fb413c7638 (old id 2028014)
date added to LUP
2011-07-21 11:16:52
date last changed
2017-07-30 04:23:29
@article{43a5e530-64bc-46e6-8dfa-30fb413c7638,
  abstract     = {The potential of Fe-V-oxide catalysts for use in methanol oxidation is explored. Our results show that although FeVO4 is active and selective for formaldehyde formation, it is not completely stable towards volatilization under reaction conditions. Attempts to stabilize Fe-V-oxide were made using titania, alumina and silica supports. However, we observe that although some stabilization is achieved using titania and alumina, the supported catalysts are sensitive to volatilization considering the relatively low content of active oxide. Compared with supported V-oxide, the results show that iron causes stabilization of vanadium decreasing its volatility. Considering the observation that the neat FeVO4 restructures to form a spinel-type phase under influence of the catalysis, we prepared a series of cation vacant spinel-type Fe3-x-yVx□yO4 catalysts with various V/Fe ratio and consequent number of cation vacancies □. Opposed to the activity, which is rather constant irrespectively of the vanadium content, the selectivity to formaldehyde passes through a maximum of about 90% for Fe/V = 14. A spinel-type phase with the composition Fe2.62V0.19□0.20O4 was prepared and subsequently preoxidized to different degree. It is observed that the spinel-type structure is stable and that the oxidation of vanadium and iron is balanced by an increasing number of cation vacancies. Moreover, irrespectively of the original degree of preoxidation, it is found that in methanol oxidation a steady state is reached where all samples are equally active and selective and have the same composition both in the bulk and at the surface. The results clearly demonstrate that the spinel-type catalysts are phase-stable, nonvolatile and flexible in that the cations can change oxidation state retaining the same basic structure type and Fe/V ratio.},
  author       = {Massa, Mariano and Häggblad, Robert and Andersson, Arne},
  issn         = {1572-9028},
  keyword      = {Oxidation,Methanol,Formaldehyde,Fe-V-oxide catalysts,Cation vacant spinel-type Fe3-x-yVx□yO4 catalysts,Volatility,XANES,XPS,XRD},
  language     = {eng},
  number       = {10-12},
  pages        = {685--697},
  publisher    = {Kluwer},
  series       = {Topics in Catalysis},
  title        = {Cation vacant Fe(3-x-y)V(x)□(y)O(4) spinel-type catalysts for the oxidation of methanol to formaldehyde},
  url          = {http://dx.doi.org/10.1007/s11244-011-9690-1},
  volume       = {54},
  year         = {2011},
}