Alkaline Synthesis of Pure Silica ITH Zeolite for Vapor Phase Beckmann Rearrangement of Cyclohexanone Oxime.

Abstract

Pure silica ITH zeolite is normally synthesized under neutral or acidic conditions in the presence of HF, but it is challenging for synthesis of this zeolite under alkaline conditions. In this work, it is successful for alkaline synthesis of pure silica ITH in the absence of HF using a designed organic template containing F species, showing that the sample obtained has high crystallinity associated with ITH structure, nanosheet morphology, and rich silanol nests. Very importantly, this ITH zeolite exhibited better performance in vapor phase Beckmann rearrangement of cyclohexanone oxime than that of Silicalite-1 zeolite, one of the best catalysts for this reaction. This work might offer a new opportunity for preparation of pure silica zeolites as efficient catalysts in the Beckmann rearrangement in the future.