Efficient glucose dehydration to HMF onto Nb-BEA catalysts

Abstract The one-pot production of HMF from glucose was investigated in pure hot water and biphasic water/methylisobutylketone (MIBK) solvent using mesoporous Nb(0.02 and 0.05 mol%)-Beta zeolites obtained by a post synthesis methodology. The mesoporous Nb-Beta zeolites present residual framework Al-acid sites, extra-framework isolated Nb(V) and Nb 2 O 5 pore-encapsulated clusters in which Nb(V)O-H exhibit moderate strength Bronsted acidity. After optimization, the dehydration of glucose onto the Nb-modified Beta-zeolites occurred with a selectivity of 84.3% in HMF for a glucose conversion of 97.4%. This result has been obtained in a biphasic water/MIBK solvent and in the presence of NaCl, at 180 °C, after 12 h.