Oxidovanadium(IV) acetylacetonate immobilized onto CMK-3 for heterogeneous epoxidation of geraniol

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Dorbes, S (Author) Other; Pereira, C (Author) FCUP; Andrade, M (Author) Other; Barros, D (Author) Other; Pereira, AM (Author) FCUP; Rebelo, SLH (Author) FCUP; Araujo, JP (Author) FCUP; Pires, J (Author) Other; Carvalho, AP (Author) Other; Freire, C (Author) FCUP

Journal

Title: Microporous and Mesoporous Materials

Vol. 160

Pages: 67-74

ISSN: 1387-1811

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 39 Citations

Scopus - 39 Citations

Scientific classification

FOS: Engineering and technology > Materials engineering

Other information

Authenticus ID: P-002-5FV

DOI: 10.1016/j.micromeso.2012.03.041

Abstract (EN): Heterogeneous catalysts based on oxidovanadium(IV) acetylacetonate ([VO(acac)(2)]) immobilized onto nanostructured ordered carbon material CMK-3 were prepared using two different strategies: (i) direct anchoring of the metal complex through the surface oxygen groups of the pristine support (CAT I) and (ii) immobilization via 3-aminopropyltriethoxysilane spacer previously grafted onto the support (CAT II). The metal complex immobilization through both methods was confirmed by X-ray photoelectron spectroscopy, elemental analysis. Fourier transform infrared spectroscopy and thermogravimetry. Xray diffraction (XRD) analysis provided insights on the materials rod-like structure and suggested the existence of some expansion of the CMK-3 network upon the complex immobilization. The new materials were tested as heterogeneous catalysts in the epoxidation of geraniol using tertbutyl hydroperoxide as oxidant leading to substrate conversions higher than 98% after 2.5 h and 98-99% selectivity for the 2,3-epoxygeraniol product. The improved catalytic performance observed for the new materials when compared to other heterogenized [VO(acac)(2)] based catalysts was attributed to an efficient mass transfer provided by the rod-like structure of CMK-3 supports. When APTES was used as the linker for complex immobilization (CAT II), negligible catalyst leaching and higher substrate conversions were observed when compared to CAT I upon recycling and reuse. Furthermore, XRD provided evidence for the preservation of the rod-like structure of the support upon the catalytic reactions.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8