Cyclohexanone ammoximation via in situ H2O2 production using TS-1 supported catalysts

Abstract

The ammoximation of cyclohexanone to the corresponding oxime via in situ H₂O₂ formation offers an attractive alternative to the current industrial means of production, overcoming the significant economic and environmental concerns associated with the manufacture of a key reagent, H₂O₂. Herein we demonstrate the efficacy of a composite catalyst, consisting of precious metal nanoparticles supported on a commercial TS-1, towards the in situ synthesis of cyclohexanone oxime, bridging the wide condition gap that exists between the two distinct reaction pathways: H₂O₂ direct synthesis and cyclohexanone ammoximation. In particular, the alloying of Au with Pd and the introduction of low concentrations of Pt into AuPd nanoalloys are found to be key in promoting high catalytic performance. The improved catalytic activity of optimal catalysts is found to result from a combination of a disruption of contiguous Pd ensembles and the modification of Pd oxidation states, which in turn dictate catalytic activity towards the production and subsequent degradation of H₂O₂.