Dendrimer-mediated formation of Cu-CuOx nanoparticles on silica and their physical and catalytic characterization

Gustavo Larsen, Sandra Noriega

Research output: Contribution to journalArticle

43 Scopus citations

Abstract

Copper-silica catalysts were synthesized by impregnation of sol-gel derived silicas containing entrapped DAB-Am-64 dendrimer as both chelating and pore-templating agent, with methanolic copper nitrate solutions. Basic materials characterization included X-ray diffraction (XRD), transmission electron microscopy (TEM), and nitrogen adsorption. The metallic and monovalent copper contents were determined by N2O decomposition and CO adsorption, respectively. The N2O decomposition reaction and CO adsorption were followed by mass spectrometry (MS) and thermogravimetry in an oscillating balance reactor (OBR). Diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) was used to monitor the modes of co-adsorption of N 2O and CO as a function of temperature. The N2O + CO temperature-programmed reaction indicates that the copper oxidation state changes under reaction, and as a consequence a transition in reaction regime occurs as temperature increases. Control of the ultimate particle size of Cu species, while heavily influenced by the dendrimer especially at lower Cu:dendrimer ratios, is not exact. Factors such as calcination and reduction temperatures needed to be investigated in order to maximize the impact of dendrimer complexation on the final state of the catalyst.

Original languageEnglish (US)
Pages (from-to)73-81
Number of pages9
JournalApplied Catalysis A: General
Volume278
Issue number1
DOIs
Publication statusPublished - Dec 28 2004

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Keywords

  • CO adsoiption
  • Copper dispersion
  • Dendrimer
  • NO decomposition

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

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