Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)wa...Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)was pretreated with 10%H_(2)SO_(4)by single factor optimization to increase specific surface area and pore volume obviously.The catalytic ozonation performance of ACF loaded with Au,Ag,Pt and Pd noble metals on ethyl acetate was investigated and Pd/ACF was selected as the optimal catalyst which had certain stability.Pd is uniformly distributed on the surface of ACF,and Palladium mainly exists in the form of Pd0 with a amount of Pd+2.The specific surface area of the catalysts gradually decreases as the loading increases.The activation energy of ethyl acetate calculated by Arrhenius equation is 113 kJ mol 1.With 1%Pd loading and the concentration ratio of ozone to ethyl acetate is 3:1,catalytic ozonation performance is maximized and the conversion rate of ethyl acetate reached to 60%in 3050℃Cat 15,00030,000 h^1.展开更多
Waste pickling liquors （WPLs） containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation-oxidation method for iron recovery by Fe...Waste pickling liquors （WPLs） containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation-oxidation method for iron recovery by Fe304 nanoparhcle＇ production from the WPLs was developed in this study. 2＋All oxidation-reduction potential monitoring method was developed for real-time control of the Fe2＋/Fe3＋ molar ratio. The key coprecipitation-oxidation parameters were determined using the orthogonal experimental design method. The use of promoters greatly improved the Fe3O4 nanoparticle crystallinity, size, magnetization, and dispersion. X-ray diffraction patterns showed that the produced Fe3O4. nanoparticles were single phase. The Fe3O4 nan oparticles were approximately spherical and slightly aggtomerated. Vibrating sample magnetometry showed that the Fe3O4 nanopahicles produced from the WPLs had good magnetic properties, with a saturation magnetization of 80.206 emu. g-1 and a remanence of 10.500 emu. g-1. The results show that this novel coprecipitation-oxidation method has great potential for recycling iron in WPLs.展开更多
基金the National Key R&D Program of the Ministry of Science and Technology,China(Grant No.2018YFC0705304)and the Key Scientific and Technological Support Projects,Tianjin City,China(Grant No.19YFZCSF01090).
文摘Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)was pretreated with 10%H_(2)SO_(4)by single factor optimization to increase specific surface area and pore volume obviously.The catalytic ozonation performance of ACF loaded with Au,Ag,Pt and Pd noble metals on ethyl acetate was investigated and Pd/ACF was selected as the optimal catalyst which had certain stability.Pd is uniformly distributed on the surface of ACF,and Palladium mainly exists in the form of Pd0 with a amount of Pd+2.The specific surface area of the catalysts gradually decreases as the loading increases.The activation energy of ethyl acetate calculated by Arrhenius equation is 113 kJ mol 1.With 1%Pd loading and the concentration ratio of ozone to ethyl acetate is 3:1,catalytic ozonation performance is maximized and the conversion rate of ethyl acetate reached to 60%in 3050℃Cat 15,00030,000 h^1.
文摘Waste pickling liquors （WPLs） containing high concentrations of iron and acid are hazardous waste products from the steel pickling processes. A novel combined coprecipitation-oxidation method for iron recovery by Fe304 nanoparhcle＇ production from the WPLs was developed in this study. 2＋All oxidation-reduction potential monitoring method was developed for real-time control of the Fe2＋/Fe3＋ molar ratio. The key coprecipitation-oxidation parameters were determined using the orthogonal experimental design method. The use of promoters greatly improved the Fe3O4 nanoparticle crystallinity, size, magnetization, and dispersion. X-ray diffraction patterns showed that the produced Fe3O4. nanoparticles were single phase. The Fe3O4 nan oparticles were approximately spherical and slightly aggtomerated. Vibrating sample magnetometry showed that the Fe3O4 nanopahicles produced from the WPLs had good magnetic properties, with a saturation magnetization of 80.206 emu. g-1 and a remanence of 10.500 emu. g-1. The results show that this novel coprecipitation-oxidation method has great potential for recycling iron in WPLs.
