resumo
Microporous silicoaluminophosphates SAPO-5, SAPO-11 and SAPO-40 have been tested as solid acid catalysts in the dehydration of xylose into furfural (FUR) under biphasic aqueous-organic conditions, at 170 degrees C. For all materials, no decrease in catalytic activity is observed after three consecutive recycling runs. Furfural yields at 4 h using SAPO-11 (34-38%) are comparable with that for HMOR zeolite with Si/Al similar to 6 (34%), under similar reaction conditions, while H(2)SO(4) (0.03 M) gives 2% FUR. Complete xylose conversion is reached within 16-24 h, with furfural yields of up to 65%. Bronsted and Lewis acidity of the silicoaluminophosphates was determined through FTIR analysis of adsorbed pyridine, and tentatively correlated with the catalytic performances.
palavras-chave
LIQUID-PHASE DEHYDRATION; SOLID ACID CATALYSTS; 12-TUNGSTOPHOSPHORIC ACID; MOLECULAR-SIEVES; ZEOLITE; FRUCTOSE; GLUCOSE; SAPO-5
categoria
Chemistry
autores
Lima, S; Fernandes, A; Antunes, MM; Pillinger, M; Ribeiro, F; Valente, AA
nossos autores
Anabela Tavares Aguiar Valente
Investigador Principal
Maria Margarida Feitor Pintão Moreno Antunes
Investigador Júnior
Martyn Pillinger
Investigador JúniorGrupos
1 - nanomateriais inorgânicos funcionais e híbridos orgânico-inorgânico
4 - biorrefinarias, materiais de origem biológica e reciclagem
agradecimentos
This work was partly funded by the FCT, POCTI and FEDER (project POCTI/QUI/56112/2004 and PTDC/QUI/71198/2006). The authors thank Prof. C.P. Neto for helpful discussions, Dr. Z. Lin (CICECO) for supplying a mordenite sample, and Dr. F. Domingues for access to HPLC equipment. S.L. and M.M.A. are grateful to the FCT for grants.