Activating molecular oxygen with Au/CeO for the conversion of lignin model compounds and organosolv lignin.

Au/CeO was demonstrated to be a high efficiency catalyst for the conversion of 2-phenoxyacetophenol (PP-ol) employing O as an oxidant and methyl alcohol as the solvent without using an erosive strong base or acid. Mechanistic investigations, including emission quenching experiments, electron spin-resonance (ESR) and intermediate verification experiments, were carried out. The results verified that the superoxide anion activated by Au/CeO from molecular oxygen plays a vital role in the oxidation of lignin model compounds, and the cleavage of both the β-O-4 and C-C linkages was involved.