MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. ...MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. The manganese valence in MOAO was ＋4, indicative of MnO2 being coated on the surface of MA during the impregnation process. MOAO had a large specific surface area （385.266 m^2/g） and wormhole-like mesoporous structure. The average pore size, which could be precisely controlled over the range of 3.4-4.1 nm. The optimum removal of fluoride was obtained when the initial pH was in the range of 4-10. The defluorination efficiency of MOAO was far superior to that of MA when the initial fluoride concentration exceeded 40 mg/L. The large surface area and bimodal porous structure of MOAO after coating MnO2 may be responsible for the high removal efficiency in the defluorination process.展开更多
In this study, the improvement in the removal of chlorobenzene （C6H5Cl） in the air was investigated by combining dielectric barrier discharge （DBD） driven by bipolar pulse-power with catalysts. Molecular sieve 4A ...In this study, the improvement in the removal of chlorobenzene （C6H5Cl） in the air was investigated by combining dielectric barrier discharge （DBD） driven by bipolar pulse-power with catalysts. Molecular sieve 4A （MS-4A） and MnO2/γ-Al2O3 （MnO2/ALP） as two kinds of catalysts were tested at different positions in a DBD reactor. Catalysts were located either in the discharging area between two electrodes, or just behind the discharging area （in the afterglow area） closed to the outlet. The results indicated that DBD reactor with a bipolar pulse power-supply produced strong instant discharge and energetic particles, which can effectively activate catalysts of MS-4A and MnO2/ALP located in the afterglow area to achieve the synergistic effects on effective fission of chemical bonds of chlorobenzene. It was considered that the gas-chlorobenzene and the chlorobenzene adsorbed on the catalysts were decomposed simultaneously.展开更多
文摘MnO2-Al2O3 （MOAO） binary nanocomposite with a 1：3 MnO2 to Al2O3 molar ratio was synthesized by impregnation technique using mesoporous alumina （MA） precursor. The MOAO product consisted of MA and amorphous MnO2. The manganese valence in MOAO was ＋4, indicative of MnO2 being coated on the surface of MA during the impregnation process. MOAO had a large specific surface area （385.266 m^2/g） and wormhole-like mesoporous structure. The average pore size, which could be precisely controlled over the range of 3.4-4.1 nm. The optimum removal of fluoride was obtained when the initial pH was in the range of 4-10. The defluorination efficiency of MOAO was far superior to that of MA when the initial fluoride concentration exceeded 40 mg/L. The large surface area and bimodal porous structure of MOAO after coating MnO2 may be responsible for the high removal efficiency in the defluorination process.
基金National Natural Science Foundation of China(No.50678031)
文摘In this study, the improvement in the removal of chlorobenzene （C6H5Cl） in the air was investigated by combining dielectric barrier discharge （DBD） driven by bipolar pulse-power with catalysts. Molecular sieve 4A （MS-4A） and MnO2/γ-Al2O3 （MnO2/ALP） as two kinds of catalysts were tested at different positions in a DBD reactor. Catalysts were located either in the discharging area between two electrodes, or just behind the discharging area （in the afterglow area） closed to the outlet. The results indicated that DBD reactor with a bipolar pulse power-supply produced strong instant discharge and energetic particles, which can effectively activate catalysts of MS-4A and MnO2/ALP located in the afterglow area to achieve the synergistic effects on effective fission of chemical bonds of chlorobenzene. It was considered that the gas-chlorobenzene and the chlorobenzene adsorbed on the catalysts were decomposed simultaneously.
