Structural and Redox Properties of Vanadium Complexes in Molten Salts of Interest for the Catalytic Oxidation of Sulfur Dioxide

S. Boghosian, A. Chrissanthopoulos, Rasmus Fehrmann

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


Electronic absorption (UV/VIS) spectra have been obtained at 450 degrees C from V2O5-K2S2O7 molten mixtures in SO2 ( P-SO2 = 0 - 1.2 atm) gas atmospheres. The data are in agreement with the V-V reversible arrow V-IV equilibrium: (VO)(2)O(SO4)(4)(4-)(l) + SO2(g) - 2VO(SO4)(2)(2-)(l) + SO3(g). Sulfur dioxide does not coordinate to the V-V complex but starts significantly to coordinate to V-IV for P-SO2 > 0 4 atm in accordance with the equilibrium: VO(SO4)(2)(2-)(l) + SO2(g) reversible arrow VO(SO4)(2)SO22-(l). Furthermore, high temperature Raman spectroscopy has been used to establish the structural and vibrational properties of the vanadium complexes formed in the molten salt-gas system V2O5-M2S2O7-M2SO4/SO2-O-2 (M = K or Cs). The spectral features and the exploitation of the relative Raman intensities indicate that the (VO)(2)O(SO4)(4)(+) dimeric complex unit which possesses a V-O-V bridge is formed in the V2O5-M2S2O7 molten mixtures. Interaction with SO2 or addition of sulfate leads to cleavage of the V-O-V bridge and formation of the (VO)-O-IV(SO4)(2)(2-) or (VO2)-O-V(SO4)(2)(3-) complex units respectively. The most prominent Raman bands due to the V-V and V-IV complexes formed are assigned and the spectral data are discussed in terms of possible structural models.
Original languageEnglish
Title of host publicationTwelfth International Symposium on Molten Salts
EditorsP. Trulove, et al.
Place of PublicationPennington, N.J., USA
PublisherThe Electrochemical Society
Publication date2000
ISBN (Print)1-56677-264-8
Publication statusPublished - 2000
EventTwelfth International Symposium on Molten Salts - Honolulu, Hawaii, United States
Duration: 17 Oct 199922 Oct 1999
Conference number: 12


ConferenceTwelfth International Symposium on Molten Salts
CountryUnited States
CityHonolulu, Hawaii
SeriesElectrochemical Society Series

Fingerprint Dive into the research topics of 'Structural and Redox Properties of Vanadium Complexes in Molten Salts of Interest for the Catalytic Oxidation of Sulfur Dioxide'. Together they form a unique fingerprint.

Cite this