论文部分内容阅读
通过对Pt-Al_2O_3的分散度、活性中心数和其环己烷脱氢反应和环戊烷氢解反应性能的关联,证明Pt-Al_2O_3的低温吸附氢中心是环已烷脱氢反应的活性中心,而这种吸附中心的较强部位即是环戊烷氢解反应的活性中心。减少这种中心的数目抑制了正庚烷氢解反应,而脱氢芳构化反应活性和选择性却提高了。这一事实说明,正庚烷氢解反应也发生在Pt-Al_2O_3的低温吸附氢中心上,而脱氢芳构化反应则发生在另一种中心上。这两种反应是平行的竞争反应。根据以上情况提出,正庚烷脱氢芳构化反应很可能是发生在Pt和Al_2O_3有较强相互作用的高温吸附氢中心上。
Through the correlation analysis of Pt-Al 2 O 3 dispersion, number of active sites, cyclohexane dehydrogenation reaction and cyclopentane hydrogenolysis reaction, it was proved that the Pt-Al 2 O 3 low-temperature adsorbed hydrogen center is the active center of cyclohexane dehydrogenation reaction , While the stronger part of this adsorption center is the active center of cyclopentane hydrogenolysis reaction. Decreasing the number of such centers suppresses the n-heptane hydrogenolysis, whereas the dehydroaromatization reactivity and selectivity are increased. This fact shows that n-heptane hydrogenolysis also occurs at the Pt-Al 2 O 3 low-temperature adsorption hydrogen center, while the dehydroaromatization reaction occurs at another center. The two reactions are parallel competitive reactions. According to the above, it is proposed that the dehydrogenation aromatization of n-heptane is likely to occur at the high-temperature adsorptive hydrogen center where Pt and Al 2 O 3 strongly interact with each other.