resumo
Mesoporous aluminosilicates of the type Al-TUD-1, prepared via "green", low-cost, non-surfactant templating routes, are effective and versatile heterogeneous acid catalysts for the production of useful bio-based furanic ethers and levulinate esters, via the reactions of the biorenewable substrates 5-hydroxymethyl-2-furfural (Hmf) or furfuryl alcohol (FA) with aliphatic alcohols. The identification of reaction intermediates and products by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry was carried out, giving mechanistic insights. Ethyl levulinate (EL) was formed from FA or Hmf as substrates, with higher EL yields being reached in the former case. Different types of alkyl levulinates may be synthesized from FA using Al-TUD-1 catalysts. On the other hand, 5-(ethoxymethyl)furan-2-carbaldehyde may be formed as the main product from Hmf. Modifications of the properties of Al-TUD-1 involved varying the Si/Al ratio and applying a post-synthesis acid treatment. The influence of these factors and of the reaction conditions on the catalytic reactions was investigated. The efficient regeneration and recyclability of Al-TUD-1 was assessed.
palavras-chave
ETHYL LEVULINATE; FURFURYL ALCOHOL; SOLID-ACID; MESOPOROUS ALUMINOSILICATE; CONVERSION; ETHERIFICATION; EFFICIENT; TRANSFORMATION; DISACCHARIDES; SURFACTANTS
categoria
Chemistry; Science & Technology - Other Topics
autores
Neves, P; Antunes, MM; Russo, PA; Abrantes, JP; Lima, S; Fernandes, A; Pillinger, M; Rocha, SM; Ribeiro, MF; Valente, AA
nossos autores
Anabela Tavares Aguiar Valente
Investigador Principal
Maria Margarida Feitor Pintão Moreno Antunes
Investigador Júnior
Martyn Pillinger
Investigador Principal
Patrícia Alexandra Ferreira Russo
Bolseiro de pós-Doutoramento
Patrícia dos Santos Neves
Investigador Auxiliaragradecimentos
We are grateful to Fundacao para a Ciencia e a Tecnologia (FCT), Programa Operacional Ciencia e Inovacao (POCI) 2010, Orcamento do Estado (OE), Fundo Europeu de Desenvolvimento Regional (FEDER) for general funding (project POCTI/QUI/56112/2004), and to CICECO (PEst-C/CTM/LA0011/2013) and QOPNA (Research Unit 62/94, project PEst-C/QUI/UI0062/2013). We acknowledge the FCT for post-doctoral grants to P.N. (SFRH/BPD/73540/2010), M. M. A. (SFRH/BPD/89068/2012), P. A. R (SFRH/BPD/79910/2011) and S. L. (SRFH/BPD/23765/2005). The authors thank Magda Santos for the assistance in the GC x GC-ToFMS analyses.