5-Hydroxymethylfurfural (HMF) is an important platform chemical that can be obtained from biomass by acid catalysis. In the current investigation, an acceleration of the dehydration of fructose to HMF with an increased reaction rate and decreased activation energy is identified over the adjacent acid sites in MFI-type zeolites. The spatial proximities of these sites become prominent with the decrease of the Si/Al ratio in HZSM-5 and increase the charge density on the adsorbed reactant molecule according to C-13 MAS NMR results. The cooperative catalysis by the adjacent acid sites is deduced and it is very important to develop new effective acid catalysts. (C) 2014 Elsevier Inc. All rights reserved.