摘要
采用溶胶凝胶法制备不同金属元素比例素比例的前驱体,并将得到的前驱体分别在400、500、600℃焙烧得到铁镍双金属氧化物(Fe-NiO_x)催化剂。以邻苯二甲酸二甲酯(DMP)降解率为标准衡量焙烧温度、金属元素比例制备的Fe-NiO_x催化剂活化过硫酸盐(PMS)的能力,同时探讨体系中PMS与DMP浓度比、Fe-NiO_x催化剂投量对异相催化体系氧化能力的影响。结果显示:前驱体焙烧温度为400、500℃时,催化剂能力基本相同,DMP降解率分别为16.54%、17.84%;当温度上升至600℃,DMP降解率显著提升至35.35%,表明600℃得到的催化剂具备更强的活性。在600℃条件下焙烧制得的不同金属元素比例的Fe-NiO_x催化剂,c(Fe)∶c(Ni)=1∶4、1∶2、1∶1、2∶1、4∶1,DMP降解率分别为22.61%、32.63%、35.35%、38.60%、39.14%,Fe相对含量的增加提升了体系氧化能力,可能是催化剂表面成分因Fe增加而发生改变及多价态之间的循环促进反应。PMS与DMP浓度比例由5∶1上升至20∶1时,DMP降解率达到45.79%,继续提升浓度比促进作用不显著,增加催化剂投量DMP降解率与改变反应物浓度比具有相似的趋势,确定最佳实验条件为PMS与DMP浓度比为20∶1、Fe-NiO_x催化剂投量为200 mg/L。投加自由基抑制剂叔丁醇(TBA)、乙醇(EA),DMP降解率由49.85%分别降至21.44%、19.24%,表明体系中产生氧化物的主要为羟基自由基(·OH)及少量硫酸根自由基(·SO-4)。
In order to prepare a varies of Fe-Ni bimetal oxides(Fe-NiO_x) catalysts by sol-gel method,the precursor of different Fe,Ni mole ratio was calcined at 400,500,600 ℃.Catalytic ability of Fe-NiO_xcatalysts with different calcination temperature and metal element mole ratio was measured by the degradation rate of dimethyl phthalate(DMP) during the oxidation process.Influence of Fe-NiO_xcatalysts dosage as well as mole ratio between peroxomonosulfate(PMS) and DMP was also investigated so as to study the suitable experimental conditions.The results showed that catalysts calcined at 400 ℃ and 500 ℃ had have nearly the same DMP degradation rate which was is 16.54%,17.84%,respectively,while that of catalysts calcined at 600 ℃ increased sharply to 35.35%.Adding catalysts of c(Fe)∶c(Ni)=1∶4,1∶2,1∶1,2∶1,4∶1,DMP degradation rate was 22.61%,32.63%,35.35%,38.60% and 39.14%,so it could be seen that catalytic ability of different catalysts was in proportion to the relative content of Fe during the synthesis process.Raising ratio of PMS and DMP from 5∶1 to 20∶1,DMP degradation rate increased to 45.79%,and the amount of DMP hardly decreased when the ratio reached 30∶1.Increasing the dosage of Fe-NiO_xcatalysts,DMP degradation rate had a similar trend to that of different reactant ratio.Therefore,the optimal conditions of the system was that the ratio of PMS and DMP was 20∶1 and dosage of Fe-NiO_xcatalysts was 200 mg/L.Adding tert butyl alcohol(TBA),ethyl alcohol(EA) which was radical scavenger of different radicals,the degradation of DMP decreased from 49.85% to 21.44% and 19.24%,respectively,indicating that the active substance was mainly hydroxyl radicals(·OH) and there was a little sulfate radicals(·SO_4^-).
出处
《四川大学学报（工程科学版）》
CSCD
北大核心
2017年第S1期202-206,共5页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(51508353)
成都市科技惠民资助项目(2015-HM01-00279-SF)
