Antimony Oxide-Modified Vanadia-Based CatalystssPhysical Characterization and Catalytic Properties Full article
| Journal |
The Journal of Physical Chemistry B
ISSN: 1520-6106 , E-ISSN: 1520-5207 |
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| Output data | Year: 2001, Volume: 105, Number: 44, Pages: 10772-10783 Pages count : 12 DOI: 10.1021/jp012228u | ||||||||
| Tags | SOLID-STATE REACTION; ORTHO-XYLENE; SELECTIVE OXIDATION; O CATALYSTS; V-51 NMR; SURFACE; AMMOXIDATION; REACTIVITY; V2O5; SPECTRA | ||||||||
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| Affiliations |
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Funding (2)
| 1 | International Association for the Promotion of Co-operation with Scientists from the New Independent States of the Former Soviet Union | IR-97-0059 |
| 2 | Russian Foundation for Basic Research | 01-03-32364 |
Abstract:
Antimony-modified vanadia-on-titania catalysts were prepared for the selective oxidation of o-xylene to phthalic anhydride by ball milling of powder mixtures followed by calcination. A binary Sb2O3−V2O5 system was also prepared for comparison purposes. The resulting materials were physically characterized by surface area measurements, X-ray diffraction analysis (XRD), laser Raman spectroscopy, X-ray absorption fine structure (XAFS) spectroscopy, electron spin resonance (ESR), magnetic susceptibility determination, and 15V solid-state NMR. The catalytic performance of the TiO2-supported materials was tested for o-xylene oxidation. After calcination of the Sb2O3−V2O5 binary mixture at 673 K, Sb3+ is almost quantitatively oxidized to Sb5+, while both V3+ and V4+ are detected. V3+ and some V4+ are most likely located in a nonstoichiometric VSbO4-like structure, while the majority of V4+ preferentially concentrates within shear domains in oxygen-deficient V2O5-x particles. In the titania-supported catalyst system, both Sb2O3 and V2O5 spread on the anatase surface. Sb3+ is oxidized to Sb5+, and V3+, V4+, and V5+ are detected. VSbO4-like structures are not observed. The presence of antimony leads to the formation of presumably V3+−O−V5+ redox couples. The paramagnetic centersin contrast to the binary mixtureare largely isolated. Antimony preferentially migrates to the surface and appears to exhibit a dual function catalytically. It is inferred from the experimental data that the addition of antimony leads to site isolation and to a reduction of surface acidity. We suggest that V−O−V−O−V domains or clusters are interrupted by incorporation of Sb to form V−O−Sb−O−V species. As a consequence of this site isolation and a reduction of surface acidity, overoxidation of o-xylene is reduced. These two effects are therefore most probably responsible for the improved selectivity of the ternary catalyst system over the binary one toward phthalic anhydride.
Cite:
Spengler J.
, Anderle F.
, Bosch E.
, Grasselli R.K.
, Pillep B.
, Behrens P.
, Lapina O.B.
, Shubin A.A.
, Eberle H.-J.
, Knözinger H.
Antimony Oxide-Modified Vanadia-Based CatalystssPhysical Characterization and Catalytic Properties
The Journal of Physical Chemistry B. 2001. V.105. N44. P.10772-10783. DOI: 10.1021/jp012228u WOS Scopus РИНЦ ANCAN OpenAlex
Antimony Oxide-Modified Vanadia-Based CatalystssPhysical Characterization and Catalytic Properties
The Journal of Physical Chemistry B. 2001. V.105. N44. P.10772-10783. DOI: 10.1021/jp012228u WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jun 13, 2001 |
| Published print: | Nov 1, 2001 |
Identifiers:
| Web of science: | WOS:000172049100006 |
| Scopus: | 2-s2.0-0035829918 |
| Elibrary: | 41817433 |
| Chemical Abstracts: | 2001:722188 |
| Chemical Abstracts (print): | 136:20263 |
| OpenAlex: | W1985084446 |