Applied Catalysis B: Environmental, Vol.110, 216-220, 2011
Solvent-free aerobic alcohol oxidation using Cu/Nb2O5: Green and highly selective photocatalytic system
Photooxidation of alcohols without organic solvents in the presence of O-2 took place at the atmospheric pressure and room temperature over Nb2O5 and Cu/Nb2O5, avoiding the cost, toxicity, and purification problems associated with transition-metal systems. Loading of a small amount of copper on Nb2O5 significantly enhanced activity without lowering selectivity. On the other hand, loading of Pt, Ni, Rh, Ru, and Ag showed no promotion effect. The selectivities of the photooxidation of aliphatic, aromatic and heteroatom-containing alcohols over Cu/Nb2O5 were in the range of 80-99%. Cu/Nb2O5 was easily separated from the reaction mixture and was reusable without reducing the catalytic performance. (C) 2011 Elsevier B.V. All rights reserved.