Causes of activation and deactivation of modified nanogold catalysts during prolonged storage and redox treatments

Ekaterina Kolobova, Yulia Kotolevich, Ekaterina Germanovna Pakrieva, Grigory Mamontov, Mario H. Farias, Nina Bogdanchikova, Vicente Cortes Corberan, Alexey Pestryakov

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

The catalytic properties of modified Au/TiO2 catalysts for low-temperature CO oxidation are affected by deactivation and reactivation after long-term storage and by redox treatments. The effect of these phenomena on the catalysts was studied by HRTEM, BET, SEM, FTIR CO, XPS and H2 TPR methods. The main cause for the deactivation and reactivation of catalytic properties is the variation in the electronic state of the supported gold, mainly, the proportion of singly charged ions Au+ . The most active samples are those with the highest proportion of singly charged gold ions, while catalysts with a high content of trivalent gold ions are inactive at low-temperatures. Active states of gold, resistant to changes caused by the reaction process and storage conditions, can be stabilized by modification of the titanium oxide support with transition metals oxides. The catalyst modified with lanthanum oxide shows the highest stability and activity.

Original languageEnglish
Article number486
JournalMolecules
Volume21
Issue number4
DOIs
Publication statusPublished - 1 Apr 2016

Keywords

  • Catalyst deactivation
  • Catalyst reactivation
  • Co oxidation
  • Effect of storage
  • Gold catalysts
  • Support modification

ASJC Scopus subject areas

  • Organic Chemistry

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