New Heterogeneous Polyoxometalate Based Mesoporous Catalysts for Hydrogen Peroxide Mediated Oxidation Reactions

Maxym V. Vasylyev, Ronny Neumann

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217 Citations (Scopus)

Abstract

Inorganic-organic hybrid mesoporous materials were prepared by cocrystallization of a "sandwich" type polyoxometalate, [ZnWZn 2(H2O)2(ZnW9O34) 2]12-, and branched tripodal organic polyammonium salts, tris[2-(trimethylammonium)ethyl]-1,3,5-benzenetricarboxylate or 1,3,5-tris[4-(N,N,N-trimethylammonium-ethylcarboxyl)phenyl]benzene trications. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed formation of three-dimensional perforated coral-shaped amorphous materials with the organic cations surrounding polyoxometalate anions. N 2 sorption analysis showed that the hybrid materials have a BET surface area of ∼30-50 m2 g-1 and an average pore diameter of 36 Å leading to the classification of these materials as mesoporous materials with moderate surface areas. These hybrid materials behaved as very effective and selective heterogeneous catalysts for the epoxidation of allylic alcohols and oxidation of secondary alcohols to ketones with hydrogen peroxide as oxidant. The activity and selectivity of the heterogeneous catalysts based on the hybrid materials was similar to those of homogeneous catalysts based on the same [ZnWZn2(H2O) 2(ZnW9O34)2]12- polyoxometalate.

Original languageEnglish
Pages (from-to)884-890
Number of pages7
JournalJournal of the American Chemical Society
Volume126
Issue number3
DOIs
Publication statusPublished - Jan 28 2004

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ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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