Highly selective conversion of glucose into furfural over modified zeolites

Furfural is industrially produced from hemicellulose-derived pentoses, the production of furfural from hexoses is technologically challenging. In the present work, modified versions of zeolite beta containing iron, tin, or zirconium site were prepared from H-Beta via ion-exchanged route. XRD, TEM, SEM, N-2 adsorption-desorption, ICP-AES and pyridine FTIR spectroscopy techniques were used to characterize these materials. All these catalysts possess high specific surface areas and adequate acidities, with both Brensted and Lewis acid sites. The prepared modified beta zeolites were then used as catalysts for converting C-6 carbohydrates to furfural in gamma-valerolactone (GVL). The reactions were quite selective for furfural, with furfural as the predominant product and 5-HMF as the main by-product. Promising results were achieved for Sn-Beta, which could optimize the furfural yield from glucose up to 69.2% at 453 K for 33 min. The improved activity and selectivity of the catalysts were correlated with their suitable textural and acidic properties. Moreover, the results revealed that reaction solvent played a key role in mediating sugars conversion and product species. Finally, the stability and regeneration of the catalyst were also evaluated. (C) 2016 Elsevier B.V. All rights reserved.