铁硅酸盐分子筛乙苯氧化脱氢催化性能研究──平衡阳离子性质及水热处理对反应活性的影响

Studies on Catalysis of Ferrosilicates for OxidationDehydrogenation of Ethylbenzene ──Effect of Exchanged Cations and Hydrothermal Treatment on Actlvity

在８２３Ｋ和乙苯／Ｏ_２＝１．０的条件下考察了乙苯在ＦｅＺＳＭ－５上的催化活性。比较了平衡阳离子性质、水热处理及Ｆｅ_２Ｏ_３的分散程度对乙苯氧化脱氢性能的影响。结合ＸＰＳ、ＥＳＲ及ＴＰＲ测试结果讨论了ＦｅＺＳＭ－５中铁的存在状态与乙苯氧化脱氢的关系。结果表明，ＦｅＺＳＭ－５催化剂上作为Ｌ酸中心的骨架Ｆｅ（Ⅲ）、水热处理产生的高分散非骨架Ｆｅ（Ⅲ）和适当强度的碱中心共同构成了乙苯氧化脱氢活性中心。

The catalytic activity and selectivity of FeZSM-5 catalysts for oxidation-dehydrogenation of ethylbenzene(EB) were examined at 823 K and EB:O2=1. 0. The influence of exchanged cations, hydrothermal treatment and dispersity of Fe2O3 on oxidation-dehydrogenation activity of EB over FeZSM-5 was also studied. XPS, ESR and TPR techniques were used for the determination of states and properties of iron in FeZSM-5. The results indicate that framework iron and highly dispersed nonframework iron used as Lewis acidic sites and basic sites with suitable strength construct the active centers of EB oxidation-dehydrogenation.