Conversion of cellulose to lactic acid via oxidation pretreatment combined with catalysis by MoO₃/Sn-Beta

Synthesis of chemicals from abundant cellulose is an environmental-friendly route for the biomass conversion. Herein, lactic acid was synthesized from cellulose firstly with an oxidation pretreatment and then through a catalytic process with MoO₃/Sn-Beta as the catalyst. During the first step, partial hydroxymethyl groups on cellulose were oxidized by molecular oxygen to the carboxyl acid groups, which acted as the active sites for the following catalytic depolymerization of cellulose. During the second step, conversion of the oxidized cellulose was performed in water with MoO₃/Sn-Beta as a catalyst. The hydrolysis of cellulose to glucose was catalyzed by the formed carboxyl acid groups; then, glucose was converted to lactic acid over the Lewis acid sites of MoO₃/Sn-Beta. Yield of 21.4% to lactic acid was given at 180 °C for 8 h.