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对铈、钼助催的Fe_2O_3-K_2O乙苯脱氢制苯乙烯催化剂使用前后和工业用后卸下的样品作XPS研究,结果表明:用后催化剂中铁以Fe~(2+)和e~(3+)两种价态并存,表面上生成一定量羟基,反应条件下钾和氧化铁发生作用生成新相K_2Fe_2O_4,它也是活性相,表面钾被水蒸汽溶解随物料流动而迁移流失,钾的流失是失活的重要原因,还有结构因素的影响,在催化剂表面铈以CeO_2微晶存在,反应条件下部分被还原,因而增加了晶格氧的活动性和电子传递渠道,通过促进氧转移脱氢而使催化剂脱氢活性增加。
X-ray diffraction (XPS) studies on samples of styrene and molybdenum-catalyzed dehydrogenation of Fe 2 O 3 -K 2 O to ethylbenzene dehydrogenated styrene before and after commercial and industrial use showed that Fe 2+ and e ~ 3+), two kinds of valence coexist and a certain amount of hydroxyl groups are formed on the surface. Under the reaction conditions, potassium and iron oxide react to form a new phase, K 2 Fe 2 O 4, which is also an active phase. The surface potassium is dissolved by steam and migrates with the flow of material, Loss is an important cause of inactivation, as well as the influence of structural factors. Cerium is present as CeO 2 crystallites on the catalyst surface and partially reduced under the reaction conditions, thereby increasing lattice oxygen activity and electron transport channels by promoting oxygen transfer Dehydrogenation increases the dehydrogenation activity of the catalyst.