Catalyst deactivation during α-pinene isomerization, Fe-Mn-promoted sulfated zirconium oxide

This works studies the deactivation of zirconium oxide, promoted by iron and manganese catalysts (SZFM), during the alpha -pinene isomerization. Experiments were done in liquid phase by using a batch reactor, and the solid crystalline structure was studied by XRD while the acidity by FTIR. The deactivated catalyst exhibited coke deposits and lost its Bronsted acidity, though it still kept its crystalline structure. The nature of the coke deposit formed was analyzed by infrared spectroscopy (FTIR) as well as by Temperature Programmed Oxidation (TPO). Regeneration was done in air flow, where the temperature required to restore Bronsted acidity and to totally eliminate the coke deposits was of about 873 K.