镍钴双金属氧化物催化过硫酸氢钾效能和机理

发布时间：2018-11-24 15:03

【摘要】：为了探究双金属催化剂对PMS(过硫酸氢钾)强氧化活性的活化效果,以酸性橙7(AO7)为目标污染物,采用溶胶-凝胶法(sol-gel method)制备Co-NiO_x(镍钴双金属氧化物)催化剂,考察了镍钴催化剂的活性以及催化PMS降解AO7的影响因素;并对其反应机理进行了探究。结果表明,Co-NiO_x催化PMS氧化AO7的效果明显优于单金属催化,以及单独氧化。随着催化剂投量的增加,AO7降解率明显增大;AO7的降解率随着PMS初始浓度的增加而增大,且150μmol/L为最佳投量。当AO7初始浓度从32μmol/L逐渐升至96μmol/L,在反应20 min时AO7降解率由92.5%降至67.07%;初始pH在4左右时AO7有最大降解率95.02%。添加乙醇(EA)和叔丁醇(TBA)的自由基抑制剂试验结果表明,氧化体系中起主要氧化作用的是SO_4~-·(硫酸根自由基)。XPS结果显示,Co-NiO_x催化剂中Co、Ni主要以Co~(2+)、Ni~(2+)的形式存在,O主要以表面羟基氧、吸附氧和水的形式存在。研究表明,Co-NiO_x催化剂具有良好的催化性能,能够有效活化PMS产生SO_4~-·和·OH,进而实现对水体污染物的降解。
[Abstract]:In order to investigate the activation effect of bimetallic catalyst on the strong oxidation activity of PMS (potassium persulfate), acid orange 7 (AO7) was used as the target pollutant. Co-NiO_x (nickel-cobalt bimetallic oxide) catalyst was prepared by sol-gel method (sol-gel method). The activity of Ni-Co catalyst and the factors influencing the degradation of AO7 by PMS were investigated. The reaction mechanism was also discussed. The results show that the effect of Co-NiO_x on PMS oxidation of AO7 is better than that of monometallic catalyst and single oxidation. With the increase of the amount of catalyst, the degradation rate of AO7 increases obviously, and the degradation rate of AO7 increases with the increase of initial concentration of PMS, and 150 渭 mol/L is the best dosage. When the initial concentration of AO7 increased from 32 渭 mol/L to 96 渭 mol/L, the degradation rate of AO7 decreased from 92.5% to 67.07% at 20 min, and the maximum degradation rate of AO7 was 95.02% at about 4 min. The experimental results of free radical inhibitor by adding ethanol (EA) and tert-butanol (TBA) showed that the main oxidant in the oxidation system was SO_4~- (). XPS of sulfate radical showed that Co, in Co-NiO_x catalyst) Ni exists mainly in the form of Co~ (2) and Ni~ (2), and O exists mainly in the form of surface hydroxyl oxygen, adsorbed oxygen and water. The results show that the Co-NiO_x catalyst has good catalytic performance and can effectively activate PMS to produce SO_4~- and OH, to achieve the degradation of pollutants in water.
【作者单位】：四川大学建筑与环境学院;
【基金】：国家自然科学基金(51508353) 成都市科技惠民项目(2015-HM01-00279-SF) 大学生创新创业训练计划(201610611024)资助
【分类号】：X703

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