Synthesis of TS-1 submicrocrystals from inorganic reactants by a seed method for the vapor Beckmann rearrangement of cyclohexanone oxime

Abstract

The size of molecular sieve crystals will significantly affect their catalytic performances. In this paper, TS-1 submicrocrystals (SMCs) have been size-controllably synthesized using S-1 and TS-1 seeds in a tetrapropylammonium bromide (TPABr)–ammonia system. The sizes of TS-1 were effectively controlled by the seeds. For the same type of seeds, the smaller one provided smaller TS-1 SMCs. The TS-1 SMCs using S-1 seeds was smaller than those using similar size TS-1 seeds. The crystallinity behavior, microstructure, morphology of the TS-1 SMCs and coordination states of Ti were affected by S-1 or TS-1 seeds. The TS-1 SMCs were examined as catalysts in the vapor phase Beckmann rearrangement of cyclohexanone oxime. The highest catalytic performances including conversion of cyclohexanone oxime and selectivity to ε-caprolactam were obtained over the TS-1 SMCs synthesized with nano S-1 seed.