A series of environmentally benign nanocrystalline Cu/Al₂O₃ catalysts for the direct formation of H₂O₂ from CO, H₂O and O₂ have been developed by a novel liquid-phase chemical reduction method and characterized by TEM, XRD, and N₂O titration. A maximum H₂O₂ formation rate of 0 236 mmol·(g-cat)^-1·h^-1 was achieved over the catalyst with average Cu particle size of 15 nm, suggesting the presence of a significant size effect on the performance of the Cu/Al₂O₃ catalysts.

Key words: environmentally benign, nanocrystalline Cu/Al₂O₃ catalyst, direct production, carbon monoxide, hydrogen peroxide