Highly efficient and selective aerobic oxidation and direct oxidative esterification of alcohols and furanics by tunable and recyclable Au nanoparticles on porous polymer

An Au-polymer nanoreactor . Gold nanoparticles supported on porous poly(2,6-dimethyl-1,4-phenylene oxide) (AuNPs-PPO) were developed as a robust, tunable catalyst for aerobic oxidation and oxidative esterification of alcohols and furan-based renewable platforms. A polymer-incarceration strategy yields small Au nanoparticles (∼5 nm) uniformly dispersed in the PPO matrix, generating electron-deficient Au(δ⁺) sites, as shown by XPS and CO-probed FT-IR. In water under mild conditions, AuNPs-PPO enables highly selective oxidation of benzylic and allylic alcohols to aldehydes/ketones, while the hydrophobic polymer microenvironment suppresses over-oxidation of primary alcohols to acids. Furfuryl alcohol is converted to furfural or, by tuning temperature, catalyst loading, and solvent composition, to oxidative cleavage products (maleic and formic acids). HMF oxidation affords either DFF or FDCA with excellent selectivity, governed by polymer swelling and water availability. Direct oxidative esterification of HMF provides methyl 5-(hydroxymethyl)-2-furoate and dimethyl 2,5-furandicarboxylate with excellent TOF. The catalyst is stable and readily recyclable, offering a versatile and sustainable platform for producing industrially relevant oxygenated compounds in a sustainable way.