关键词: 活化条件, 铂, SO42?/ZrO2-Al2O3, 正己烷, 异构化

Abstract: Pt/SO42?/ZrO2-Al2O3 (PSZA) catalyst was prepared by impregnating SO42?/ZrO2-Al2O3 with H2PtCl6. The effect of activation condition on n-hexane isomerization activity of PSZA catalyst was investigated. The catalyst was characterized by temperature-programmed oxidation (TPO-MS), temperature-programmed nitrogen treatment (TPN-MS) and temperature-programmed reduction (TPR-MS). The n-hexane isomerization activity of the catalyst was evaluated in a continuous flow fixed bed reactor. The experiment results showed that the conversion of n-hexane over PSZA was about 85% when it was activated in air at the temperature ranging from 200 ℃ to 500 ℃. However, the catalyst hardly possessed the isomerization activity when PSZA was activated in nitrogen at above 300 ℃. The reduction pretreatment at a high temperature above 300 ℃ led to the great decrease in catalytic activity. It was proposed that the role of activation in air at a high temperature was not only removal of water on the catalyst, but also re-oxidation of catalyst surface, which led to high catalytic activity. However, the pre-treatment in hydrogen gas at a high temperature led to the loss of sulfur species over PSZA, resulting in significant decrease in catalytic activity. The suitable activation condition was as follows：pretreatment in air at the temperature ranging from 300 ℃ to 500 ℃ and reduction in hydrogen gas at 250 ℃.

Key words: activation condition, Pt, SO42?/ZrO2-Al2O3, n-hexane, isomerization