CeO2/NaY催化剂的氧合及其催化氧化脱硫性能

采用等体积浸渍法制备了一系列CeO₂/NaY催化剂，重点考察了焙烧温度和铈负载量对催化剂活性组分结构及性能的影响。通过拉曼（Raman）光谱、X射线衍射（XRD）、低温N₂吸附-脱附（BET）、高分辨透射电子显微镜（HR-TEM）以及氢气程序升温还原（H₂-TPR）等技术对催化剂的结构、形貌和化学性能进行了表征分析。结果表明，焙烧温度与铈负载量对于铈物种在分子筛载体表面及孔道内的分散形态和与载体的相互作用有着重要影响，进而影响催化剂中铈物种的氧合性能与氧化脱硫性能。在常温常压下的氧合性能测试，催化剂最大储氧量为每克催化剂1.44 mmol O₂。在反应温度100 ℃，催化剂用量0.20 g，以正辛烷为溶剂二苯并噻吩初始浓度为500 μg·g^-1的模拟油样20 mL，氧气流量为50 mL·min^-1的条件下，反应240 min二苯并噻吩转化率可达90.10%，二苯并噻吩被氧化为二苯并噻吩砜。因此，发展稀土改性分子筛催化剂，应用于以分子氧为氧化剂的油品氧化深度脱硫，对探究绿色高效的油品氧化脱硫技术具有积极意义。

Oxygenation and Oxidation Desulfurization Properties of CeO2/NaY Catalysts

CeO₂/NaY catalysts were prepared by incipient wetness impregnation. The influence of the calcination temperature and Ce content on the crystallinity and performance of the active species of the catalysts was studied in this paper. The synthesized catalysts were characterized by Raman spectroscopy, X-ray diffraction (XRD), low temperature nitrogen adsorption-desorption (Brunauer-Emmett-Teller (BET)), highresolution transmission electron microscopy (HR-TEM), and H₂-temperature-programmed reduction (H₂-TPR). The results indicate that the calcination temperature and the Ce content have an important influence on the morphology of the cerium species and whether they can be uniformly dispersed on the surface and channels of the zeolite, and on the interaction between the cerium species and zeolites, which affects the oxygenation and oxidation desulfurization properties of the cerium species of the catalysts. The oxygenation properties of the prepared catalysts are tested under normal temperature and atmospheric pressure. The maximum oxygen storage capacity is 1.44 mmol·g^-1. The conversion rate of dibenzothiophene (DBT) reaches up to 90.10% within 240 min when a 20 mL mixture of octane and DBT as a model oil is treated by the addition of 0.20 g catalyst under 50 mL·min^-1 of oxygen flow at 100 ℃. The initial concentration of DBT is 500 μg·g^-1. The oxidation product is dibenzothiophene sulfone (DBTO₂). Therefore, it is of great significance to develop zeolites modified by rare earth elements to complex as functionalized catalysts with molecular oxygen for deep desulfurization of fuel oil, which can be easily done by air or oxygen oxidation without secondary pollution.