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

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

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

Revista

Título: Microporous and Mesoporous Materials

Vol. 160

Páginas: 67-74

ISSN: 1387-1811

Editora: Elsevier

Indexação

ISI Web of Knowledge - 39 Citações

Scopus - 39 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8