Oxygen Bridged Bimetallic CuMoO 4 Nanocatalyst for Benzylic Alcohol Oxidation; Mechanism and DFT Study

Though concept of oxygen bridged bimetallic catalyst for organic reaction is not well understood. Herein, we have tried to explain the concept by experimental as well as its support by full DFT study. We report here a competent protocol for dehydrogenative oxidation of benzylic alcohol using an oxygen bridged bimetallic CuMoO 4 nano catalyst. Careful demonstration reveals that oxidation is not effective either with mono‐metallic Cu (II) or Mo(VI); instead combination of both the metals through the oxygen bridge [Cu−O−Mo] unexpectedly and interestingly catalyzed the reaction efficiently. The new concept is strongly supported by computational DFT study. DFT study reveals dehydrogenative oxidation is preferred at copper centre over molybdenum and aromatic benzyl alcohols are greatly stabilised. Interaction barrier energy of monometallic CuO and MoO 3 catalyst is much higher than bimetallic CuMoO 4 . Hydrogen transfer has larger barrier heights for CuO (31.5 kcal/mol) and MoO 3 (40.3 kcal/mol) than bimetallic CuMoO 4 .