Abstract Catalytic oxidation is considered one of the best methods to remove volatile organic compounds. One of the main advantages of catalytic combustion is the low emissions of minor contaminants released to the atmosphere and low operative cost, followed by high removal properties for pollutants, compared to adsorption and incineration. The purpose of this paper is to review the behaviour of a group of catalysts extracted mainly from the location of Cerro Largo (Banado de Medina), Uruguay, through evaluation of the total combustion of toluene. The montmorillonite was pillared with a polycation of Al13, with a Keggin-like structure using conditions to ensure a molar ratio OH−/Al3+ of 2 and then the resulting pillared clay was washed, calcined, and used as support of the active catalytic phase. The catalysts contain manganese oxide (as Mn2O3) which was obtained from Mn(CH3COO)2.4H2O. Catalysts were obtained by incipient wetness impregnation method and heated from room temperature to 550 °C, then maintained at this temperature for 4 h in air atmosphere. The resulting catalysts and support were characterized by thermogravimetric analysis, X-ray diffraction, N2-physisorption at 77 K, temperature programmed reduction, elemental analysis, scanning electron microscopy and transmission electron microscopy. The catalytic tests were performed in a fixed bed reactor using 0.5 g of sample, operating at atmospheric pressure and a feed of a mixture consisting of 192 cm3/min of Ar, 8 cm3/min of O2 and 2000 ppmv of toluene. Catalytic tests were carried out using a ramp mode from 200 °C to 500 °C with a heating rate of 1 °C/min. Samples from the reactor outlet stream were taken every 50 min and the reaction products were analyzed by gas chromatography. Based on the results of the X-ray analysis, the manganese found in the catalysts is in the form of Mn2O3. All the catalysts were active, and the gaseous by-products were CO2 and H2O in all cases. The best catalytic performance was obtained with the catalyst containing 40% of Mn2O3 on the pillared clay (90% conversion at 300 °C). No decrease in catalytic activity was observed when analysing the stability test for 24 h. Thus, it is possible to conclude that the catalyst obtained shows good catalytic performance and high stability in the combustion of toluene.

中文翻译：

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从乌拉圭粘土中获得的 PILC-Al 作为介孔 MnOx 催化剂的载体对甲苯燃烧的利用

摘要 催化氧化被认为是去除挥发性有机化合物的最佳方法之一。与吸附和焚烧相比，催化燃烧的主要优点之一是释放到大气中的少量污染物排放量低，运营成本低，其次是污染物的高去除性能。本文的目的是通过评估甲苯的总燃烧来回顾主要从乌拉圭 Cerro Largo (Banado de Medina) 位置提取的一组催化剂的行为。蒙脱石用 Al13 的聚阳离子柱撑，具有类 Keggin 结构，使用条件确保 OH-/Al3+ 的摩尔比为 2，然后将所得柱撑粘土洗涤、煅烧并用作活性催化相的载体。催化剂含有从 Mn(CH3COO)2.4H2O 中获得的氧化锰（作为 Mn2O3）。通过初湿浸渍法获得催化剂，并从室温加热到 550°C，然后在空气气氛中在该温度下保持 4 小时。所得催化剂和载体通过热重分析、X 射线衍射、77 K 下的 N2 物理吸附、程序升温还原、元素分析、扫描电子显微镜和透射电子显微镜进行表征。催化测试在固定床反应器中进行，使用 0.5 g 样品，在大气压下操作，加入由 192 cm3/min 的 Ar、8 cm3/min 的 O2 和 2000 ppmv 的甲苯组成的混合物。使用从 200 °C 到 500 °C 的斜坡模式以 1 °C/min 的加热速率进行催化测试。每 50 分钟从反应器出口流中取样并通过气相色谱分析反应产物。根据 X 射线分析的结果，在催化剂中发现的锰以 Mn2O3 的形式存在。所有催化剂都是活性的，在所有情况下，气态副产物都是 CO2 和 H2O。在柱撑粘土上含有 40% Mn2O3 的催化剂（在 300°C 下转化率为 90%）获得了最佳催化性能。当分析稳定性测试 24 小时时，未观察到催化活性降低。因此，可以得出结论，所得催化剂在甲苯燃烧中表现出良好的催化性能和高稳定性。在催化剂中发现的锰以 Mn2O3 的形式存在。所有催化剂都是活性的，在所有情况下，气态副产物都是 CO2 和 H2O。在柱撑粘土上含有 40% Mn2O3 的催化剂（在 300°C 下转化率为 90%）获得了最佳催化性能。当分析稳定性测试 24 小时时，未观察到催化活性降低。因此，可以得出结论，所得催化剂在甲苯燃烧中表现出良好的催化性能和高稳定性。在催化剂中发现的锰以 Mn2O3 的形式存在。所有催化剂都是活性的，在所有情况下，气态副产物都是 CO2 和 H2O。在柱撑粘土上含有 40% Mn2O3 的催化剂（在 300°C 下转化率为 90%）获得了最佳催化性能。当分析稳定性测试 24 小时时，未观察到催化活性降低。因此，可以得出结论，所得催化剂在甲苯燃烧中表现出良好的催化性能和高稳定性。当分析稳定性测试 24 小时时，未观察到催化活性降低。因此，可以得出结论，所得催化剂在甲苯燃烧中表现出良好的催化性能和高稳定性。当分析稳定性测试 24 小时时，未观察到催化活性降低。因此，可以得出结论，所得催化剂在甲苯燃烧中表现出良好的催化性能和高稳定性。