Preparation method of superacid catalyst and application of superacid catalyst in sulfur-free ammonium rearrangement reaction

Abstract

This invention discloses a method for preparing a superacid catalyst and its application in the ammonium sulfate-free rearrangement reaction. The preparation method includes the following steps: (1) metal oxide (M x O y (1) The precursor undergoes a complexation reaction with the phosphonophenylcarboxylic acid ligand to form an M-P complex; (2) The phosphorus-containing complex is calcined under a nitrogen atmosphere to obtain M x O y -P2O5-C-based powder; (3) SO4 is prepared by treating the solid powder obtained in step (2) with sulfuric acid. 2‑ / M x O y -P2O5-C; (4)SO4 2‑ / M x O y The -P2O5-C catalyst is used to catalyze the Beckmann rearrangement reaction of cyclohexanone oxime to produce caprolactam. The SO4 provided by this invention... 2‑ / M x O y In the Beckmann rearrangement catalysis of cyclohexanone oxime, the P2O5-C catalyst achieved a maximum cyclohexanone oxime conversion of 98.1% and a maximum caprolactone selectivity of 99.5%, demonstrating good catalyst stability.

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