The oxidative aromatization of class="a-plus-plus">n-hexane over VMgO catalysts

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• 作者：Jonathan Chetty ; Venkata D. B. C. Dasireddy…
• 关键词：VMgO ; Oxidative dehydrogenation ; n ; Hexane ; Benzene ; Total dehydrogenation selectivity
• 刊名：Reaction Kinetics, Mechanisms and Catalysis
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：120
• 期：1
• 页码：307-321
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Catalysis; Physical Chemistry; Industrial Chemistry/Chemical Engineering;
• 出版者：Springer Netherlands
• ISSN：1878-5204
• 卷排序：120

文摘

Vanadium magnesium oxide (VMgO) catalysts with different vanadium loadings were synthesized and tested for catalytic activity in the oxidative dehydrogenation of n-hexane. High surface area catalysts were obtained by the wet impregnation technique. Magnesium oxide (MgO) and magnesium orthovanadate [Mgb>3b>(VOb>4b>)b>2b>] were the only phases observed in each catalyst. All the catalysts were tested at 0.6–7.8 % of n-hexane in air within a temperature range of 350–550 °C, varying the gas hourly space velocities. Catalytic testing conducted below the lower flammability limit (0.6 % n-hexane in air) showed only benzene and carbon oxides in the product stream, whereas for experiments done above the upper flammability limit (7.8 % n-hexane in air), hexenes, in addition to benzene and carbon oxides were observed. Decreasing the feed composition from 7.8 to 5.5 % resulted in higher yields towards benzene and total dehydrogenated products. The effect of variations in the gas hourly space velocity investigated using the 19 wt% vanadium catalyst and a feed concentration of 7.8 % showed that the selectivity to benzene increased slightly with an increase in the gas hourly space velocity.