摘要
挥发性有机污染物(VOCs)的治理是环保的重要课题,催化氧化是十分有效的治理技术.为开发高效的催化剂,以甲苯为研究对象,采用简便的共沉淀法制备一系列Fe掺杂的ε-MnO2 催化剂.其中,Fe1Mn5 对甲苯氧化的催化活性最高,转化率为 90%时的反应温度t90 为 237℃.此外,该催化剂表现出优异的长期运行稳定性和良好的耐水性.通过一系列表征分析,结果表明,Fe 的掺杂促进了 Fe1Mn5 氧化物上氧空位的产生,提升了催化剂表面吸附氧物种比例,从而提高了其低温还原性.同时,原位红外分析结果表明,Fe掺杂所产生的表面吸附氧物种促进了甲苯甲基的快速脱氢过程,并促进芳香环中C═C键的断裂.
Abstract
The treatment of volatile organic pollutants(VOCs)is an important topic of environmental protection,and catalytic oxidation is a very effective treatment technology.In order to develop efficient catalysts,a series of Fe-doped ε-MnO2 catalysts were prepared by a facile coprecipitation method and used to catalyze the oxidation of toluene.Fe1Mn5 exhibited the highest catalytic activity for toluene oxidation(t90=237℃),and also showed excellent long-term stability and water resistance.A series of characterization analysis was carried out and revealed that Fe doping promoted the generation of oxygen vacancies on Fe1Mn5 oxide,increased the proportion of surface oxygen species,and thus improved its low-temperature reducibility.Meanwhile,in situ DRIFTS analysis results showed that the surface adsorbed oxygen species produced by Fe doping promoted the rapid dehydrogenation of methyl group of toluene and facilitated the breaking of C=C bond in aromatic ring.
万方数据