College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
Beijing Municipal Environmental Monitoring Center, Beijing 100048, China.
J Environ Sci (China). 2020 Oct;96:194-203. doi: 10.1016/j.jes.2020.05.002. Epub 2020 Jun 2.
In this paper, KMnO was used to pre-treat CoFe-layered double hydroxides (LDH) precursor to prepare MnO decorated CoFeO catalyst. The toluene oxidation performance of the catalyst was investigated systematically. The optimized 0.1MnCF-LDO catalyst exhibited the best catalytic performance, and the temperatures of 50% and 90% toluene conversion (T and T) were 218 and 243°C, respectively. The apparent activation energy (E) was 31.6 kJ/mol. The characterization results showed that the pre-redox reaction by KMnO could increase the specific surface area, Co species amount and oxygen defect concentration of the catalyst, which are the main reason of the improved toluene catalytic activity. Besides, this method was also applied to enhance toluene oxidation of iron mesh based monolithic catalyst. The 0.1MnCF-LDO/Iron mesh (IM) catalyst showed a 90% toluene conversion at around 316°C which was much lower than that of without MnO addition (359°C). In addition, the water resistant of all the catalysts was studied as well, all the samples showed relatively good water resistance. The toluene conversion still remained to be over >80% even in the presence of 10 vol.% water vapor.
本文采用 KMnO₄预处理 CoFe 层状双氢氧化物（LDH）前体制备 MnO 修饰的 CoFeO 催化剂，系统研究了催化剂对甲苯的氧化性能。优化后的 0.1MnCF-LDO 催化剂表现出最好的催化性能，甲苯转化率为 50%和 90%时的温度（T₅₀和 T₉₀）分别为 218 和 243°C，表观活化能（E）为 31.6 kJ/mol。表征结果表明，KMnO₄的预还原反应可以提高催化剂的比表面积、Co 物种含量和氧缺陷浓度，这是提高甲苯催化活性的主要原因。此外，该方法还被应用于提高铁网整体式催化剂的甲苯氧化性能。在 0.1MnCF-LDO/铁网（IM）催化剂上，甲苯转化率在 316°C 左右达到 90%，远低于未添加 MnO 时的转化率（359°C）。此外，还研究了所有催化剂的耐水性，所有样品均表现出较好的耐水性，即使在存在 10 vol.%水蒸气的情况下，甲苯转化率仍保持在>80%以上。
