[VO(acac)(2)] hybrid catalyst: from complex immobilization onto silica nanoparticles to catalytic application in the epoxidation of geraniol

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Clara Pereira (Author) FCUP; Jose F Silva (Author) Other; Andre M Pereira (Author) FCUP; Joao P Araujo (Author) FCUP; Ginesa Blanco (Author) Other; Jose M Pintado (Author) Other; Cristina Freire (Author) FCUP

Journal

Title: Catalysis Science and Technology

Vol. 1

Pages: 784-793

ISSN: 2044-4753

Publisher: Royal Society of Chemistry

Indexing

ISI Web of Knowledge - 48 Citations

Scopus - 52 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-XBQ

DOI: 10.1039/c1cy00090j

Abstract (EN): This work reports the preparation of a novel hybrid nanocatalyst through the immobilization of oxidovanadium(IV) acetylacetonate ([VO(acac)(2)]) onto silica nanoparticles functionalized with 3-aminopropyltriethoxysilane (APTES) and its catalytic application in the allylic epoxidation of geraniol. All the nanomaterials were characterized by chemical analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The parent and amine-functionalized silica nanoparticles were also analyzed by Si-29 and C-13 solid-state nuclear magnetic resonance and the supported [VO(acac)(2)] nanomaterial was characterized by magnetic susceptibility measurement. The APTES organosilane was grafted onto the silica nanoparticles with an efficiency of 90%, through mono-and bidentate covalent grafting. The [VO(acac)(2)] complex was covalently anchored on the surface of the APTES-functionalized silica nanoparticles with 25% of efficiency. Magnetic susceptibility measurements in combination with XPS indicated that the oxidation state of the metal center (VO2+) was preserved upon the immobilization reaction. The catalytic performance of the novel hybrid [VO(acac)(2)] nanocatalyst was evaluated in the epoxidation of geraniol, at room temperature, using tert-butyl hydroperoxide as an oxygen source. The nanocatalyst presented 100% of substrate conversion, 99% of selectivity towards the 2,3-epoxygeraniol product and was stable upon reuse in further four cycles.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10