Peng Qian, Zhong Wanling, Liu Kun, Zhang Yingjie, Xing Jiajie, Tang Xuekun
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Hunan Key Laboratory of Mineral Materials and Application, Central South University, Changsha 410083, China.
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Hunan Key Laboratory of Mineral Materials and Application, Central South University, Changsha 410083, China.
J Environ Manage. 2023 Nov 1;345:118905. doi: 10.1016/j.jenvman.2023.118905. Epub 2023 Sep 5.
The development of cobalt-based supported catalysts with high PMS catalytic activity and stability by adjusting the composition of the support is highly desirable yet remains scarce. In the work, a series of catalysts (CoAlO/AlO-xSiO) were prepared by impregnation and high-temperature calcination using AlO-xSiO with a low Si-Al ratio as the support. Measurement techniques such as XRD, XPS, UV-DRS, FTIR, BET, SEM and HRTEM were used to characterize textural and chemical properties (ratio of Co/Co, specific surface area, pore size, pore volume, etc.). The ratio of Co/Co and pore volume of CoAlO/AlO-xSiO can be turned by controlling the ratio of Si to Al, which are closely related to the catalytic performance and reusability of the catalysts. The optimized catalyst (CoAlO/AlO-0.25SiO) can completely degrade 10 mg/L p-nitrophenol (PNP) in 40 min in the pH range of 3-9 with excellent reusability. The effects of several reaction parameters (i.e., PMS dosage, CoAlO/AlO-0.25SiO dosage, reaction temperature, initial pH value, and inorganic ions) on PNP removal were comprehensively investigated. Sulfate radical (SO•) and singlet oxygen (O) are making a major contribution to the degradation of PNP. Moreover, a millimeter-scale catalyst (CoSiAl-0.25/AlO pellet) was prepared by sol adsorption and high-temperature calcination method, which maintained high oxidation activity after treatment of 18 L wastewater (PNP of 10 mg/L) in a continuous flow process. The method is simple and easy to operate on a large scale, providing a new perspective on the design and preparation of cobalt-aluminum spinel catalysts for activated PMS.
通过调整载体组成来开发具有高过一硫酸氢钾（PMS）催化活性和稳定性的钴基负载型催化剂是非常有必要的，但目前仍然很少见。在这项工作中，以低硅铝比的AlO-xSiO为载体，通过浸渍和高温煅烧制备了一系列催化剂（CoAlO/AlO-xSiO）。采用XRD、XPS、UV-DRS、FTIR、BET、SEM和HRTEM等测量技术对其结构和化学性质（Co/Co比、比表面积、孔径、孔体积等）进行了表征。通过控制硅铝比可以改变CoAlO/AlO-xSiO的Co/Co比和孔体积，这与催化剂的催化性能和可重复使用性密切相关。优化后的催化剂（CoAlO/AlO-0.25SiO）在pH值为3-9的范围内，40分钟内可完全降解10mg/L的对硝基苯酚（PNP），且具有优异的可重复使用性。综合研究了几个反应参数（即PMS用量、CoAlO/AlO-0.25SiO用量、反应温度、初始pH值和无机离子）对PNP去除的影响。硫酸根自由基（SO•）和单线态氧（O）对PNP的降解起主要作用。此外，通过溶胶吸附和高温煅烧法制备了毫米级催化剂（CoSiAl-0.25/AlO颗粒），在连续流动过程中处理18L废水（10mg/L的PNP）后仍保持高氧化活性。该方法操作简单，易于大规模应用，为活性PMS钴铝尖晶石催化剂的设计和制备提供了新的视角。
