High-yield Aromatic Monomers and Pure Cellulose Production by Oxidative Catalytic Fractionation of Lignocellulose in the presence of CuO Nanoparticles

Herein, we report the catalytic use of multifunctional CuO nanoparticles (NPs) to oxidatively fractionate lignocellulosic feedstock with dioxygen in aqueous NaOH under mild conditions . In presence of CuO NPs, lignocellulose is fractionated into three parts, overall yielding 90% carbon efficiency. Lignin is converted to up to 45.6 wt% in organic soluble aromatic aldehyde monomers, rich in vanillin and syringaldehyde, the value surpassing the theoretical one based on b-O-4 bond content, indicating significant cleavage of other ether bonds. All hemicellulose is selectively converted into water soluble small (di)acids, mainly to oxalic acid. Up to 81% of cellulose, in contrast, is obtained as a white crystalline residue with high cellulose purity (over 95%), which can readily be transformed into high quality nanocellulose, useful in many applications.