Faculty of Chemistry, Adam Mickiewicz University, Poznan, ul. Uniwersytetu Poznanskiego 8, 61-614 Poznan, Poland.
Faculty of Chemistry, Jagiellonian University, ul. Gronostajowa 2, 30-387 Kraków, Poland.
J Hazard Mater. 2021 Aug 5;415:125665. doi: 10.1016/j.jhazmat.2021.125665. Epub 2021 Mar 15.
Formation of reactive oxygen species (ROS) via HO activation is of vital importance in catalytic environmental chemistry, especially in degradation of organic pollutants. A new mixed niobium-cerium oxide (NbCeO) was tailored for this purpose. A thorough structural and chemical characterization of NbCeO along with CeO and NbO reference materials was carried out using TEM/STEM/EDS, SEM, XRD, XPS, EPR, UV-vis and N physisorption. The ability of the catalysts to activate HO towards ROS formation was assessed on the basis of EPR and Raman measurements. Catalytic activity of the oxides was evaluated in degradation of methylene blue (MB) as a model pollutant. Very high activity of NbCeO was attributed to the mixed redox-acidic nature of its surface, which originated from the synergy between Nb and Ce species. These two properties (redox activity and acidity) ensured convenient conditions for efficient activation of HO and degradation of MB. The activity of NbCeO in MB degradation was found 3 times higher than that of the commercial NbO CBMM catalyst and 240 times higher than that of CeO. The mechanism of the degradation reaction was found to be an adsorption-triggered process initiated by hydroxyl radicals, generated on the surface via the transformation of O/O.
通过 HO 激活形成活性氧物种 (ROS) 在催化环境化学中至关重要，特别是在有机污染物的降解中。为此目的专门设计了一种新型混合铌-铈氧化物 (NbCeO)。使用 TEM/STEM/EDS、SEM、XRD、XPS、EPR、UV-vis 和 N 物理吸附对 NbCeO 以及 CeO 和 NbO 参考材料进行了全面的结构和化学表征。根据 EPR 和拉曼测量评估了催化剂将 HO 激活为 ROS 形成的能力。在亚甲基蓝 (MB) 作为模型污染物的降解中评估了氧化物的催化活性。NbCeO 的高活性归因于其表面的混合氧化还原-酸性性质，这源于 Nb 和 Ce 物种之间的协同作用。这两个性质（氧化还原活性和酸度）确保了高效激活 HO 和 MB 降解的便利条件。在 MB 降解中，NbCeO 的活性比商用 NbO CBMM 催化剂高 3 倍，比 CeO 高 240 倍。发现降解反应的机制是吸附引发的过程，由表面上通过 O/O 转化生成的羟基自由基引发。
