Ce掺杂的NiCo2O4催化氧化甲苯性能研究

NiCo₂O₄是一种很前景的甲苯氧化催化剂。本文以Ce为杂原子,利用水热法制备Ce/NiCo₂O₄催化剂,以提高NiCo₂O₄尖晶石表面活性氧生成速率。采用氢气程序升温还原(H₂-TPR)、X射线光电子能谱(XPS)、X射线衍射(XRD)、比表面积测定(BET)、以及透射电子显微镜(TEM)等表征催化剂。通过改变铈掺杂量,得到最佳掺杂比例。甲苯降解实验表明,在甲苯浓度为2538ppm,空速为10000h^_-1,催化剂体积为0.5mL 时,一次水热法制备得到的15%Ce/NiCo₂O₄催化剂降解性能最优(T₉₉=267℃),在267℃下进行催化反应72h后催化剂性能无显著变化。机理研究发现,掺杂铈可提升催化剂中高价金属含量,同时催化剂良好的氧化还原性能可加快表面活性氧生成速率,从而催化性能得以提升。

Study on Catalytic Performance of Ce doping NiCo2O4 for Oxidation Toluene

Spinel oxides, e.g., NiCo2O4, are a promising catalyst for oxidation of toluene. The NiCo2O4 spinel with high active oxygen conversion rate was prepared by Ce doping, and the Ce/NiCo2O4 catalyst was successfully prepared by hydrothermal method. The catalyst was characterized by H2 temperature-programmed reduction (H2-TPR),X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), specific surface area measurement (BET), and transmission electron microscopy (TEM). The doping amount was changed to investigate the effect on catalytic oxidation performance. When the toluene concentration was 2538 ppm, the space velocity was 10000 h^-1, and the catalyst volume was 0.5 mL, the 15% Ce/NiCo2O4 catalyst preparing by once- hydrothermal possessed the optimal performance (T99=267°C) and there was no significant change in catalyst performance after catalytic oxidation at 267 °C for 72 h. The mechanism research showed that Ce-doped NiCo2O4 spinel can increase the amount of the high valence metal, which can promote the generation rate of active oxygen and further improve the catalytic performance of the catalyst.