Catalytic conversion of Kraft lignin into platform chemicals in supercritical ethanol over a Mo(OCH2CH3)x/NaCl catalyst

A Mo(OCH2CH3)x/NaCl catalyst showed high efficiency in supercritical ethanol without adding H2 in the conversion of Kraft lignin to chemicals, including C6 alcohols, C8-C10 esters, benzyl alcohols and arenes. Control experiments were done with MoCl5, NaOC2H5 and the physical mixture of them. The Mo(OCH2CH3)x/NaCl catalyst exhibited superior activity among the samples examined. The overall yield increased as the reaction temperature increased from 260° to 300°C. The yield of aromatic compounds achieved 303 mg/g lignin over the Mo(OCH2CH3)x/NaCl catalyst at 300 °C for 6 h. MoCl5 and NaOC2H5 forms Mo(OCH2CH3)x in the catalyst preparation, which behaves as the active species in Kraft lignin conversion. The primary aromatics formed from the catalytic lignin depolymerization steps may undergo secondary reactions to form the final products.