Dehydration of D-xylose into furfural catalysed by solid acids derived from the layered zeolite Nu-6(1)

A delaminated zeolite with Si/Al = 29, obtained by swelling and ultrasonication of a laminar precursor of Nu-6(2), has been examined as a solid acid catalyst for the liquid phase cyclodehydration of xylose to furfural at 170 degrees C, using a water-toluene biphasic reactor system. The final material, with a specific surface area about seven times higher than that for proton-exchanged Nu-6(2), gave a reaction rate about two times higher than that for H-Nu-6(2), and could be recycled several times without loss of performance or Al leaching. The furfural yield after 4 h reaction was 47%, compared with 34% in the presence of an H-mordenite sample with Si/Al similar to 6. (C) 2008 Elsevier B.V. All rights reserved.