MgFe2O4 Nanoparticle/Peracetic Acid Hybrids for Catalytic Oxidative Depolymerization of Lignin

Abstract

Lignin is a promising feedstock for renewable fuels and chemicalsdue to its aromatic skeleton and natural abundance. Lignin can beconverted to diverse aromatic monomers as well as dicarboxylic acidsdepending on the applied conversion technologies. Despite its greatpotential, its native and processing-induced heterogeneity and complexitylimit the conversion efficiency and product selectivity. In this study,magnesium ferrite (MgFe2O4) nanoparticle-peraceticacid (PAA) has been investigated as an efficient catalyst-oxidantincorporation for catalytic oxidative depolymerization of lignin undermild conditions. Typically, the increase in processing severity canenhance the lignin conversion while it results in the further decompositionof aromatic compounds to dicarboxylic acids. However, in this study,the incorporation of MgFe2O4 nanoparticles andPAA not only enhanced the total product yield but also improved theselectivity of aromatic monomers. The oxidative depolymerization systemusing the catalyst-oxidant combination resulted in 46 wt %of total oil product with a 61% selectivity of aromatic monomers undermild temperature (90 degrees C). In addition, this combination catalystshowed relatively good cycling stability based on the total productyield after recycling five times via magnetic separation. Overall,MgFe2O4 nanoparticles play an important roleas a co-catalyst with a PAA oxidant in the oxidative conversion oflignin with an enhanced conversion efficiency and recyclability, andit will facilitate the valorization of lignin in future bio-basedfuels and chemicals.