Catalytic conversion of fructose directly into alkyl lactate is one of the effective ways for use of biomass to produce high value-added chemicals. Research shows that one of main factors influencing the alkyl lactate yield is Lewis and Brønsted acid sites on the surface of solid acid catalysts. A series of solid acid catalysts with different acid sites and concentration is prepared

including γ-Al2O3

HZSM-5 zeolite

SnOPO4

SnZrOPO4(1:1)

and SO42-/ZrO2. All of catalysts was characterized by using NH3 temperature-programmed desorption(NH3-TPD) and infrared spectroscopy with pyridine adsorption(Py-FTIR) techniques to figure out their total acid concentration

Lewis and Brønsted acid concentrations. The catalytic conversion of fructose in methanol over the five solid acid catalysts was studied. The results showed that the conversions of fructose can be higher than 98%; product distribution obtained depends greatly on Lewis and Brønsted acid amounts; and yield of methyl lactate lessened with the decrease of Lewis acid concentration. For γ-Al2O3 catalyst that contains only Lewis acid sites

the yields of methyl lactate achieved is 24.4%

while for these solid acid catalyst that contain both Lewis and Brønsted acid sites

the product obtained is not only methyl lactate but also methyl levulinate

and yield of methyl levulinate improves with increase of Brønsted acid concentration. Finally

the product distribution from the reactions catalyzed by typical Lewis acid solid catalyst γ-Al2O3 and HZSM-5 catalyst with both Brønsted and Lewis acid sites at different reaction time was investigated. Combined with the qualitative analysis obtained by gas chromatography-mass spectrometry(GC-MS)

the reaction pathway for fructose conversion catalyzed by Lewis and Brønsted acid sites was proposed.