Classic deep oxidation CuMnOx catalysts catalyzed selective oxidation of benzyl alcohol

• An extension of classic deep oxidation CuMnOx catalysts to selective oxidation of alcohol with high efficiency. • CuMnOx catalysts characterized by Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 and CuO-Cu 1.4 Mn 1.6 O 4 oxide pairs. • Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 oxide pair is more active than CuO-Cu 1.4 Mn 1.6 O 4 oxide pair. • Rich Cu + species in Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 oxide pair is essential to achieve high catalytic activity. This work presents an extension of classic deep oxidation CuMnOx catalysts to a selective oxidation of alcohol with high efficiency and in an environmental-friendly reaction system. A series of CuMnOx catalysts characterized by CuO-Cu 1.4 Mn 1.6 O 4 and Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 oxide pairs were prepared via a novel half carbonized citrus grandis peel assisted hard template method. A shift of the oxide pairs from CuO-Cu 1.4 Mn 1.6 O 4 to Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 has been achieved by tuning Cu/Mn molar ratio, and then leads to a one-pass benzaldehyde yield more than 50% with 100% benzaldehyde selectivity in the selective oxidation of benzyl alcohol using H 2 O 2 as oxidant. Higher relative amount of Cu 1.4 Mn 1.6 O 4 in either Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 or CuO-Cu 1.4 Mn 1.6 O 4 oxide pair is found to be essential for achieving high catalytic activity. The interaction between the Cu 1.4 Mn 1.6 O 4 constituent and Mn 2 O 3 constituent of Mn 2 O 3 -Cu 1.4 Mn 1.6 O 4 oxide pair is found to able to enhance the formation of Cu + species, which can reacts with H 2 O 2 to produce •OH and then touch off a Fenton-like catalytic oxidation process of benzyl alcohol, in the current CuMnOx-H 2 O 2 system, to produce benzaldehyde with high selectivity. This work presents a new perspective in the development of highly effective and low cost CuMnOx catalysts for heterogeneous catalytic oxidation reactions.