Selective oxidation of glycerol to dihydroxyacetone over N-doped porous carbon stabilized CuxO supported Au catalysts

Abstract In this work, N-doped porous carbon stabilized CuxO (Cu-NPCs) were synthesized by a one-pot method using copper nitrate as copper precursor with the aid of Pluronic F127 under acidic condition. The characterization results confirmed that CuxO species (CuO and Cu2O) existed in NPC in a highly dispersed state due to the strong interaction between CuxO and the doped N atoms. The obtained Cu-NPCs were used as supports to prepare Au catalysts for glycerol (GLY) oxidation to dihydroxyacetone (DHA) under base-free conditions. During the reaction, GLY preferentially adsorbed onto Au nanoparticles via the secondary OH groups due to the porous characteristics of the supports, the enhanced surface basicity from the N functionalities accelerates the alkoxide formation by abstracting proton from GLY, and the surface Cu+ sites instead of Au nanoparticles activate O2 molecules to produce active oxygen species, as a result, Au/Cu-NPC-15 %-H, which is the best catalyst in Au/Cu-NPCs, exhibited much higher catalytic activity and selectivity than those of Au/CuO. Moreover, due to the stabilization of CuxO species by NPC, relatively stable surface Cu+ content, and the strong interaction between Au nanoparticles and the supports, Au/Cu-NPC-15 %-H also possessed much better catalytic stability than that of Au/CuO during four consecutive catalytic runs.