Co-Mn-Al层状双氢氧化物催化臭氧氧化水中有机污染物的活性(英文)

Catalytic Performance of Layered Double Hydroxides Co-Mn-Al for Ozonation of Organic Pollutants in Water

采用共沉淀法制备了Co-Mn-Al层状双氢氧化物,并将其用于以硝基苯为目标污染物的催化臭氧降解反应中.结果表明,Co-Mn-Al层状双氢氧化物存在时,硝基苯的降解和矿化效率较单独臭氧氧化系统显著提高.采用加入羟基自由基捕获剂(叔丁醇)和电子顺磁共振检测(5,5-二甲基-1-吡咯啉-N-氧化物为捕获剂)的间接、直接方法,探讨了Co-Mn-Al层状双氢氧化物是否强化了羟基自由基的生成.结果表明,加入叔丁醇降低了硝基苯的降解效率;电子顺磁共振检出了更强的羟基自由基加成物生成信号.Co-Mn-Al层状双氢氧化物的存在促进了羟基自由基的生成.

The catalytic activity of layered double hydroxides containing Co, Mn, and A1 for the ozonation of organic pollutants in water was investigated. The Co-Mn-A1 layered double hydroxides were prepared by coprecipitation. Nitrobenzene was used as a model compound, and it was shown that the degradation and mineralization of nitrobenzene was increased by the presence of Co-Mn-AI layered double hydroxides as compared to ozonation alone. Both an indirect method of adding a scavenger （tert-butanol） of the hydroxyl radical chain reaction and direct electron spin resonance using 5,5-dimethyl-l-pyrroline-N-oxide as a spin trapping agent were used to investigate the generation of hydroxyl radicals in the ozonation by the Co-Mn-A1 layered double hydroxides. The inhibiting effect of tert-butanol on the degradation of nitrobenzene and the detection of the stronger 5,5-dimethyl-l-pyrroline-N-oxide/hydroxyl radical adduct showed that the Co-Mn-AI layered double hydroxides catalyzed the generation of hydroxyl radicals.