A novel carbon-based solid acid, which was prepared by a facile and eco-friendly approach from glucose and p-toluenesulfonic acid (TsOH), was used to catalyze fructose dehydration into 5-hydroxymethylfurfural (HMF) for the first time and exhibits excellent catalytic performance. As high as 91.2% yield of HMF was achieved in dimethyl sulfoxide (DMSO) at 130 °C after only 1.5 h. Besides, this catalyst also displayed a good reusability.

By using cetyltrimethylammonium bromide (CTAB) as the template, a series of mesoporous niobium phosphates were synthesized at different pH values in an aqueous solution. Techniques such as small-angle X-ray diffraction, transmission electron microscopy (TEM) and N₂ sorption technique were employed to characterize the mesoporous structures of thus-synthesized materials, EDAX to detect the composition, FTIR and solid state ³¹P MAS NMR to investigate the framework information, while their acidic properties were analyzed using NH₃-TPD and pyridine-FTIR. Samples prepared at neutral to acidic conditions exhibited high surface area (213–297 m² g⁻¹), narrow pore size distribution (3–4 nm) and a great number of strong Lewis and Brönsted acid sites. These materials exhibited excellent activity in the dehydration of fructose to 5-hydroxymethylfurfural (HMF) in water. The maximum HMF yield reached 45% under 130 °C with a reaction time of 0.5 h and the yield slightly decreased to 32% after five cycles and the five-cycled catalyst can be almost regenerated by calcination at 500 °C with the yield of 40%. The excellent catalytic activity obtained in the aqueous phase can be attributed to its high acid site density and the tolerance to water.