† Electronic Supplementary Information (ESI) available: [XPS spectra, H2chemsorption results, HPLC spectra of products from Organosolv lignin conversion, effects of O2 pressure for the conversion of PP-ol, conversion of PP-one under N2 and O2, conversion of methanol under N2, and the catalytic performances of CeO2 supported Au and Pt catalysts]. SeeThe oxidative transformation of lignin into aromatic compounds is an attractive route for chemical utilization of lignocellulosic biomass. Unlike hydrogenolysis, no consumption of expensive hydrogen is required for the oxidative transformation. However, only limited successes have been achieved for the oxidative conversion of lignin. Here, we report that cerium oxide-supported palladium nanoparticles (Pd/CeO2) can efficiently catalyze the one-pot oxidative conversion of 2-phenoxy-1-phenylethanol, a lignin model compound containing β-O-4 bond and Cα-hydroxyl group, in methanol in the presence of O2, producing phenol, acetophenone and methyl benzoate as major products. Pd nanoparticles played a pivotal role in the oxidation of Cα-hydroxyl group into Cα-ketonic group, which was crucial for the transformation of the model compound. The presence of Cα-ketonic group activated the β-O-4 bond, which was subsequently cleaved over the Pd/CeO2 catalyst, affording phenol and acetophenone. At the same time, the Cα−Cβ bond also underwent oxidative cleavage catalyzed by CeO2, producing benzoic acid and further methyl benzoate. The Pd/CeO2 catalyst could also catalyze the oxidative conversion of Organosolv lignin under mild conditions (458 K), producing vanillin, guaiacol and 4-hydroxylbenzaldehyde.Scheme 1 Structures of a representative lignin fragment and lignin model compound.

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