Carbon xerogel supported noble metal catalysts for fine chemical applications

• Tipo: Artigo em Revista Científica Internacional
• Data: 2010

Autores

Bruno F. Machado (Autor) FEUP; Helder T. Gomes (Autor) Outra; Philippe Serp (Autor) Outra; Philippe Kalck (Autor) Outra; Jose L. Figueiredo (Autor) FEUP; Joaquim L. Faria (Autor) FEUP

Revista

Título: Catalysis Today

Vol. 149 Nº 3-4

Páginas: 358-364

ISSN: 0920-5861

Editora: Elsevier

Indexação

ISI Web of Knowledge - 22 Citações

ISI Web of Science

Scopus - 30 Citações

COMPENDEX

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

CORDIS: Ciências Tecnológicas

Outras Informações

ID Authenticus: P-003-9NE

DOI: 10.1016/j.cattod.2009.06.016

Abstract (EN): Carbon xerogels are mesoporous materials obtained upon pyrolysis of the dried gels resulting from polycondensation of resorcinol and formaldehyde. Treatment with nitric acid under severe conditions introduces high amounts of oxygen containing functional groups onto the surface of the material, leading however to the collapse of its porous structure. The resulting material is then used to support 1 wt.% Pt, Ir and Ru monometallic catalysts by wet impregnation using organometallic precursors. The catalysts are characterized by N(2) adsorption-desorption isotherms at 77 K, temperature programmed desorption coupled with mass spectrometry, scanning and transmission electron microscopy, and H(2) chemisorption. The liquid-phase selective hydrogenation of cinnamaldehyde to cinnamyl alcohol is used in order to assess the catalytic performance of the prepared materials. Pt and Ru catalysts are initially very selective towards the hydrogenation of the olefinic double bond, while Ir is mostly selective towards the carbonyl group. After a thermal post-reduction treatment at 973 K, selectivity towards cinnamyl alcohol is significantly improved regardless of the metal nature. The Pt catalyst exhibits the best behavior, a complete shift in C=C to C=O hydrogenation being detected. The improvement in selectivity is rationalized in terms of both an increase in metal particle size and a modification in the surface chemistry of the catalyst after the post-reduction treatment.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7