Rate and Selectivity Control in Thioether and Alkene Oxidation with H2O2 over Phosphonate-Modified Niobium(V)–Silica Catalysts

Nicholas E. Thornburg, Justin M Notestein

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Supported metal oxide catalysts are versatile materials for liquid-phase oxidations, including alkene epoxidation and thioether sulfoxidation with H2O2. Periodic trends in H2O2 activation was recently demonstrated for alkene epoxidation, highlighting Nb-SiO2 as a more active and selective catalyst than Ti-SiO2. Three representative catalysts are studied consisting of NbV, TiIV, and ZrIV on silica, each made through a molecular precursor approach that yields highly dispersed oxide sites, for thioanisole oxidation by H2O2. Initial rates trend Nb>Ti≫Zr, as for epoxidation, and Nb outperforms Ti for a number of other thioethers. In contrast, selectivity to sulfoxide vs. sulfone trends Ti>Nb≫Zr at all conversions. Modifying the Nb-SiO2 catalyst with phenylphosphonic acid does not completely remove sulfoxidation reactivity, as it did for photooxidation and epoxidation, and results in an unusual material active for sulfoxidation but neither epoxidation nor overoxidation to the sulfone.

Original languageEnglish
Pages (from-to)3714-3724
Number of pages11
JournalChemCatChem
Volume9
Issue number19
DOIs
Publication statusPublished - Oct 10 2017

Fingerprint

Niobium
Organophosphonates
epoxidation
Epoxidation
Alkenes
Sulfides
niobium
Silicon Dioxide
alkenes
Olefins
selectivity
Silica
silicon dioxide
catalysts
Oxidation
oxidation
Catalysts
Sulfones
sulfoxide
sulfones

Keywords

  • heterogeneous catalysis
  • hydrogen peroxide
  • niobium
  • oxidative desulfurization
  • supported catalysts

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Cite this

Rate and Selectivity Control in Thioether and Alkene Oxidation with H2O2 over Phosphonate-Modified Niobium(V)–Silica Catalysts. / Thornburg, Nicholas E.; Notestein, Justin M.

In: ChemCatChem, Vol. 9, No. 19, 10.10.2017, p. 3714-3724.

Research output: Contribution to journalArticle

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