Mo-doped Al2O3-ZrO2-based composite as catalyst for one-step production of alkyl-substituted monophenols from lignin via direct deoxygenation

Abstract: Different reaction conditions on the conversion of lignin and monophenol yield were investigated under the catalysis of (5% Mo)-Al₂O₃-ZrO₂; the maximum conversion rate (78.9%) and monophenol yield (31.9%) were observed at 350 °C and 0.2 g catalyst using iso-propanol, in 45 min. The GC–MS analysis revealed that the main alkyl-substituted phenols are 4-ethyl-phenol (17.7%), 4-methyl-phenol (2.303%), phenol (1.878%), etc. The ¹H NMR and FT-IR results indicated the presence of alkyl-substituted phenols in liquefaction products, and the formation mechanism of alkyl-substituted phenols was also proposed. Graphic abstract: <fig id="Figa" position="anchor"> <graphic position="anchor" specific-use="HTML" mime-subtype="PNG" href="11696_2019_1031_Figa_HTML.png" id="MO1"></graphic> </fig>