کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
56308 | 47081 | 2011 | 5 صفحه PDF | دانلود رایگان |
Zeolites La,Na-Y are important catalysts for industrial FCC units due to their acidic properties and stability. The ethylbenzene disproportionation on this zeolite was suggested as a standard test reaction for acidic zeolites by the Catalysis Commission of the International Zeolite Association (IZA). The present work provides solid-state 13C NMR spectroscopic evidence that various amounts of reactants inside the supercages of zeolites La,Na-Y obviously affect the catalytic behavior of ethylbenzene reaction. At 453 K, diphenylethane was only detected on zeolite La,Na-Y with three ethylbenzene molecules per supercage. This intermediate, however, did not occur on samples with low loading (1 or 2 EB molecules per supercage). On zeolite La,Na-Y loaded with one molecule ethylbenzene per supercage, dealkylation and realkylation of ethylbenzene occurred at 548 K without any side-reactions. However, side-reactions of oligomerization, hydride transfer, and aromatization were observed on samples with high ethylbenzene loading, which promotes the catalyst deactivation. In addition, the zeolites La,Na-Y with high loadings of ethylbenzene show a higher reactivity and more complex reaction mechanisms.
Journal: Catalysis Today - Volume 164, Issue 1, 30 April 2011, Pages 119–123