Intensification effect of peroxide hydrogen on the complete dissolution of lignocellulose under mild conditions†
Lignocellulose is generally resistant to dissolving in water and conventional organic solvents, which significantly hinders its efficient utilization. In this work, we provide a novel and efficient technology on lignocellulose dissolution under mild conditions for down-stream conversion with heterogeneous catalysts. In a mixture of hydrogen peroxide, sulfuric acid, ethanol and water, corn straw was completely dissolved in the mixture at 170 °C for 120 min without significant volatile chemical production (less than 16%). Cellulose and hemicellulose existed as water-soluble oligosaccharides in the solvent, which were more easily converted than the original polymeric carbohydrate. During the dissolved process, peroxide hydrogen exhibited a significant intensification effect on dissolving the hemicellulose, decrystallization of cellulose and delignification with sulfuric acid. Furthermore, lignin was destroyed into fragments in the course of dissolution, which had a looser structure and lower molecular weight.