Genesis of Acid鈭払ase Support Properties with Variations of Preparation Conditions: Cumene Cracking and Its Kinetics

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• 作者：Fernando Trejo ; Mohan S. Rana ; Jorge Ancheyta
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2011
• 出版时间：March 2, 2011
• 年：2011
• 卷：50
• 期：5
• 页码：2715-2725
• 全文大小：1006K
• 年卷期：v.50,no.5(March 2, 2011)
• ISSN：1520-5045

文摘

Mixed oxides (Al鈭扴i, Zr鈭扴i, Mg鈭扴i) were synthesized by the sol鈭抔el method at different gelation times. The synthesized supports were impregnated by the incipient wetness method to obtain Ni鈭扢o, Co鈭扢o, and Ni鈭扺 supported catalysts. Both the supports and catalysts were characterized by N₂ physisorption for determining textural properties, and their catalytic activities were tested with isopropyl alcohol (2-propanol) and cumene decomposition in order to evaluate their acid鈭抌ase properties. According to the obtained products, it was possible to assess qualitatively that Al鈭扴i and Zr鈭扴i supports and their respective catalysts were mainly acidic. In the case of NiMo/AlSi catalyst, high conversion during cumene cracking particularly at higher temperatures was observed. Cracking activity results indicated that surface acidity predominated due to Br酶nsted acid sites, which are mainly dependent on the support composition as well as their preparation methods. Conversion of isopropyl alcohol leads to the dehydration products, typically propylene with a very low amount of di-isopropyl ether or acetone. NiMo/AlSi catalyst was evaluated for cumene cracking and its kinetic parameters were obtained by applying the Langmuir鈭扝inshelwood model. The activation energy was found to be 27.75 kcal mol^鈭? while the heat of adsorption calculated with the Van鈥檛 Hoff equation was 鈭?4.15 kcal mol^鈭? taking into account a single-site surface reaction.