The effect of ethanol on the performance of CrO_x/SiO₂ catalysts during propane dehydrogenation

详细信息    查看全文

• 作者：Lina Li^a ; ^b ; Wenliang Zhu^a ; Lei Shi^a ; Yong Liu^a ; Hongchao Liu^a ; Youming Ni^a ; Shiping Liu^a ; ^b ; Hui Zhou^a ; ^b ; Zhongmin Liu^a ; ^{liuzm@dicp.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Propane ; Dehydrogenation ; CrOx/SiO2 catalyst ; Ethanol vapor pretreatment ; Carbon dioxide
• 刊名：Chinese Journal of Catalysis
• 出版年：2016
• 出版时间：March 2016
• 年：2016
• 卷：37
• 期：3
• 页码：359-366
• 全文大小：1383 K

文摘

The effects of ethanol vapor pretreatment on the performance of CrO_x/SiO₂ catalysts during the dehydrogenation of propane to propylene were studied with and without the presence of CO₂. The catalyst pretreated with ethanol vapor exhibited better catalytic activity than the pristine CrO_x/SiO₂, generating 41.4% propane conversion and 84.8% propylene selectivity. The various catalyst samples prepared were characterized by X-ray diffraction, transmission electron microscopy, temperature-programmed reduction, X-ray photoelectron spectroscopy and reflectance UV-Vis spectroscopy. The data show that coordinative Cr³⁺ species represent the active sites during the dehydrogenation of propane and that these species serve as precursors for the generation of Cr³⁺. Cr³⁺ is reduced during the reaction, leading to a decrease in catalytic activity. Following ethanol vapor pretreatment, the reduced CrO_x in the catalyst is readily re-oxidized to Cr⁶⁺ by CO₂. The pretreated catalyst thus exhibits high activity during the propane dehydrogenation reaction by maintaining the active Cr³⁺ states.