Deactivation and regeneration of the B2O3/TiO2-ZrO2 catalyst in the vapor phase Beckmann rearrangement of cyclohexanone oxime

The coke deposition which covers the acid sites is largely responsible for deactivation of the B2O3/TiO2-ZrO2 catalyst. After calcining in air flow at 600 °C for 8 h, the coke deposited on catalyst surface was completely burnt off and the shielded acid sites were again exposed to interact with the reactant molecules and the catalytic activity was fully recovered.