Cesium salt of a heteropolyacid in nanotubular channels and on the external surface of SBA-15 crystals: Preparation and performance as acidic catalysts

P. Madhusudhan Rao, M. V. Landau, A. Wolfson, A. M. Shapira-Tchelet, M. Herskowitz

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

The Cs-salt of heteropolyacid with stoichiometry Cs2.5H 0.5PW12O40 (CsHPW) was deposited selectively at the external surface of the SBA-15 silica microcrystals, inside its mesoporous channels and simultaneously at both location modes. The structure, texture and performance of these CsHPW/SBA-15 composites were compared with that of a reference bulk salt of the same composition. Location of CsHPW salt on the external surface of SBA-15 microcrystals leads to disintegration of its agglomerates increasing acidity of the catalytic phase. A novel preparation strategy consisting of grafting the basic Cs-species at the internal pores surface of SBA-15 stabilized the CsHPW phase inside the channels in form of 5-8 nm nanocrystals at 30-70 wt.% loadings. The catalytic tests demonstrated that insertion of the CsHPW catalytic phase inside the nanotubular channels of SBA-15 in combination with location of an additional amount of this phase at the external surface of SBA-15 microcrystals allows to increase the specific activity of this phase in MTBE synthesis, propionylation of anisole and alkylation of catechol with t-butanol by a factor of 1.5-3. This level of specific activity in combination with high total loading of catalytic phase >60 wt.% permit to get composite catalytic materials with catalytic activity higher by a factor of 1.2-1.5 with respect to the bulk CsHPW catalyst and stabilizing the catalytic phase against colloidization in polar media.

Original languageEnglish
Pages (from-to)43-55
Number of pages13
JournalMicroporous and Mesoporous Materials
Volume80
Issue number1-3
DOIs
StatePublished - 30 May 2005

Keywords

  • Acidic catalysis
  • Cesium salt
  • Heteropolyacid
  • Mesostructured silica

Fingerprint

Dive into the research topics of 'Cesium salt of a heteropolyacid in nanotubular channels and on the external surface of SBA-15 crystals: Preparation and performance as acidic catalysts'. Together they form a unique fingerprint.

Cite this