Study On The Regeneration Performance And Deactivation Mechanism Of Pt/SO₄^2-/ZrO₂Solid Superacid For N-hexane Isomerization

n-Alkanes with low octane number could be transformed into iso-alkanes with high octane number through isomerization process, which are the satisfying components in gasoline pool. The isomerization process at mediate or high temperature only produced low octane isomers due to the limitation of thermodynamic equilibrium. SO42-/ZrO2(SZ) possessed high isomerization activity at low temperature due to its super acidity and produced more multi-branch isomers with high octane number, which attracted extensive attentions.The effects of reduction condition of Pt-promoted SO42-/ZrO2-Al2O3catalyst (PSZA), Pt content over PSZA and reaction temperature on the deactivation behavior of catalyst were investigated in this dissertation. The regeneration performance of the deactivated PSZA was also studied. The physical-chemical properties of the fresh and spent catalyst were characterized by XRD, TG, Raman, TPR-MS, and so on. Combined with the reaction activity, the deactivation reason of PSZA at low reaction temperature was discussed.The experiment results indicated that the n-hexane isomerization activity of PSZA increased and the reaction stability improved as the reduction temperature increased. And the irreversible deactivation of the catalyst would be occurred when the reduction temperature was above300℃. There was no significant effect on the initial isomerization activity of PSZA when the reaction temperatures were changed, and the reaction stability increased with the reaction temperature. The conversion of n-hexane was still about80%at200℃when the reaction was continuing200hours. The deactivated PSZA after reaction at low temperature could be regenerated in hydrogen at200～250℃for several times with good catalytic activity. There were no obvious changes between fresh and deactivated catalysts of crystal structure and sulfur content, and the amount of carbon accumulation was small. The PSZA catalyst deactivated at low reaction temperature might relate with reaction mechanism, which was the hydrogen spillover in reaction was the main reason of high catalytic stability of PSZA.