Hammedi Tijani, Bensouilah Rahma, Ouakouak Abdelkader, Llorca Jordi, Cabello Francisco Medina, Ksibi Zouhaier
University of Tunis ElManar, Faculty of Sciences of Tunis, Laboratory of Materials Chemistry and Catalysis LR01ES08, Tunis, 2092, Tunisia.
Research Laboratory in Subterranean and Surface Hydraulics, University of Biskra, PO Box 145, Biskra, 07000, Algeria.
Heliyon. 2023 Oct 11;9(10):e20875. doi: 10.1016/j.heliyon.2023.e20875. eCollection 2023 Oct.
The catalytic wet air oxidation (CWAO) of p-hydroxybenzoic acid (p-HBA) was conducted in a batch reactor at 140 °C, and at a total air pressure of 50 bar over Ru-based catalysts. Four materials were selected as supports - TiO, CeO-TiO, ZrO-TiO and LaO-TiO - all of which had mesopores in their texture and pollutant adsorption capacities. The supports were prepared by the sol-gel method, and then impregnated with 3 wt% of Ru precursor. Such characterization techniques as N-sorption, XRD, XPS, H-TPR, NH-TPD, TEM, and HAADF-STEM were used to analyze the different solids. The correlation between catalytic activities and physicochemical properties was discussed. A significant specific surface area (S), a large amount of surface-active oxygen, and Lewis acidity sites were observed on cerium-containing catalysts (Ru/CeTi). Fresh Ru catalysts containing cerium showed higher activity than Ru/TiO, Ru/ZrTi, and Ru/LaTi catalysts. It is assumed that the acidic sites and surface oxygen trap the p-HBA molecule, thus increasing the catalytic properties of the Ru particles which interact with the surface oxygen through the cerium redox process (Ce/Ce). As the presence of cerium increases surface-active oxygen, it inhibits the deposition of carbon on the surface of the Ru catalyst. The pseudo-second order (PSO) model adequately described the kinetic data of the p-HBA oxidation reaction using Ru catalysts.
对羟基苯甲酸（p-HBA）的催化湿式空气氧化（CWAO）在间歇式反应器中于140℃、总气压50巴的条件下，以Ru基催化剂进行。选择了四种材料作为载体——TiO、CeO-TiO、ZrO-TiO和LaO-TiO——它们在结构上均具有中孔且有污染物吸附能力。载体通过溶胶-凝胶法制备，然后用3wt%的Ru前驱体进行浸渍。使用N吸附、XRD、XPS、H-TPR、NH-TPD、TEM和HAADF-STEM等表征技术对不同的固体进行分析。讨论了催化活性与物理化学性质之间的相关性。在含铈催化剂（Ru/CeTi）上观察到显著的比表面积（S）、大量的表面活性氧和路易斯酸性位点。含铈的新鲜Ru催化剂比Ru/TiO、Ru/ZrTi和Ru/LaTi催化剂表现出更高的活性。据推测，酸性位点和表面氧捕获了p-HBA分子，从而提高了通过铈氧化还原过程（Ce/Ce）与表面氧相互作用的Ru颗粒的催化性能。由于铈的存在增加了表面活性氧，它抑制了碳在Ru催化剂表面的沉积。拟二级（PSO）模型充分描述了使用Ru催化剂的p-HBA氧化反应的动力学数据。
