低温等离子体结合锰基催化剂去除乙酸乙酯的研究

利用固态法和溶胶-凝胶法分别制备了钙钛矿（LaMnO₃）和八面体分子筛（OMS）两种锰基催化剂，在不同工况（输入电压、初始浓度、停留时间和催化剂放置量）条件下考察了等离子体催化对乙酸乙酯的降解特性.结果发现，锰基催化剂的加入显著提高了乙酸乙酯的去除率，减少了副产物的生成，并且OMS的催化活性高于LaMnO₃；此外，乙酸乙酯去除率随着电压的升高而增加，随着污染物初始浓度的增大而减少，并随停留时间的增长而变大；催化剂放置量为0.2 g时催化效果最佳.OMS催化剂在等离子体催化长期运行过程中表现出较好的稳定性.基于X射线衍射（XRD）、X射线光电子能谱（XPS）、H₂程序升温还原（H₂-TPR）、比表面积测试（BET）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等手段对锰基催化剂物理化学性质的分析表明，OMS具有较高的催化活性主要归功于其拥有更高比例的Mn⁴⁺/（Mn³⁺+Mn⁴⁺）和吸附氧（O_ads）/晶格氧（O_latt）.

Removal of ethyl acetate by non-thermal plasma combined with manganese-based catalysts

Two kinds of manganese-based catalysts including perovskite (LaMnO₃) and octahedral molecular sieve (OMS) were prepared by solid state method and sol-gel method, respectively. The degradation performances of ethyl acetate under various operating conditions of input voltage, initial reactant concentration, residence time and catalyst amount were investigated. The results showed that the addition of manganese-based catalysts significantly increased the removal efficiency of ethyl acetate and reduced the amount of the by-products and the catalytic activity of OMS was superior than that of LaMnO₃ in plasma-catalytic process. The removal efficiency of ethyl acetate increased with the increase of input voltage, decreased with the increase of the initial reactant concentration of pollutants, and increased with the increase of residence time. The best catalytic performance could be achieved at the catalyst amount of 0.2 g. In addition, OMS catalyst showed good stability during long-term operation in plasma-catalysis process. The superior catalytic activity of OMS stems from the high molar ratio of Mn⁴⁺/(Mn³⁺+ Mn⁴⁺) and adsorbed oxygen (O_ads)/lattice oxygen (O_latt) based on the physicochemical characterization of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H₂ temperature-programmed reduction (H₂-TPR), Brunauer-Emmett-Telle (BET) method, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).