稀土基催化材料用于含氯废气催化燃烧的研究进展

Research Progress in Catalytic Removing Chlorinated Volatile Organic Compounds by Rare Earth Materials

针对有毒有害的含氯挥发性有机化合物废气的催化氧化脱除,从稀土氧化物(Ce和La)出发,以饱和含氯代烃(二氯甲烷,二氯乙烷等)和不饱和氯代烃(氯苯,氯乙烯)为模型反应;详细分析了稀土修饰(Ce,La)或以稀土为主的催化剂(CeO_2,La MnO_3)对氯代烃催化燃烧的影响。以催化剂表面的酸性中心和氧化还原性能为主线,分析了二者在氯代烃催化燃烧反应过程中的作用,酸中心与催化剂CO选择性、积碳相关;而多氯副产物的生成和分布则受催化剂氧化性能的影响。在此基础上提出氯代烃的催化燃烧催化剂的设计思路,结合氯代烃分子结构差异,调控催化剂表面酸性中心和氧化还原性能之间的匹配,提高催化剂的低温反应活性、兼顾含碳(氯)副产物的选择性、避免催化剂积碳、氯中毒的现象,增加催化剂的稳定性。

On the catalytic removal of chlorinated volatile organic compounds, the effects of catalysts from or modified by rare earth oxides on the catalytic combustion of chlorinated volatile organic compounds （CVOCs） , such as dichloromethane, dichloroethane, vi- nyl chloride, chorobenzene, were further investigated and discussed in detail. This paper focused on the relationship between the acid- ity and redox property of the catalyst. The acidity played a key role in CO selectivity and carbon deposition ; while redox property domi- nated in the distribution of chlorinated byproducts. Based on the above dieussion, the way to design new catalysts for CVOCs combus- tion was suggested by tuning the acidity and redox property. However, the side effects of coke deposition, CO selectivity, the distribu- tion of chlorination of organic compounds needed to be considered when exploring new catalyst with high activity and stability at low temperature.