Efficient hydrolyzation of cellulose in ionic liquid by novel sulfonated biomass-based catalysts

Abstract

A green and effective approach for comprehensive hydrolyzation of cellulose has been described. Several carbon-based solid acids were successfully prepared using various biomass (glucose, microcrystalline cellulose, bamboo, and rice husk) and used to catalyze cellulose hydrolysis. The acid groups (–SO3H and –COOH) were successfully introduced onto the surface of the carbon-based solid acid catalysts as evidenced by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The structure of the prepared catalysts was characterized by scanning electron microscope and X-ray diffraction. The catalysts showed excellent catalytic performance for hydrolysis of cellulose. To improve the reaction efficiency, ball-milling and solubilization in ionic liquids of cellulose were adopted. A maximum total reducing sugar yield of 81.8 % was obtained in ionic liquid 1-butyl-3-methyl imidazolium chloride at 125 °C for 90 min when the water addition was 10 % of ionic liquid. This study provided a promising strategy to synthesize solid acids from lignocelluloses, which were further used to convert biomass into biofuels and platform chemicals.