DBD coupled with MnOx/γ-Al2O3 catalysts for the degradation of chlorobenzene

This paper investigates the degradation of chlorobenzene by dielectric barrier discharge(DBD)coupled with MnOx/γ-Al2O3 catalysts.MnOx/γ-Al2O3 catalysts were prepared using the impregnation method and were characterized in detail by N2 adsorption/desorption,x-ray diffraction and x-ray photoelectron spectroscopy.Compared with the single DBD reactor,the coupled reactor has a better performance on the removal rate of chlorobenzene,the selectivity of COx,and the inhibition of ozone production,especially at low discharge voltages.The degradation rate of chlorobenzene and selectivity of COx can reach 96.3%and 53.0%,respectively,at the specific energy density of 1350 J l-1.Moreover,the ozone concentration produced by the discharge is significantly reduced because the MnOx/Al2O3 catalysts contribute to the decomposition of ozone to form oxygen atoms for the oxidation of chlorobenzene.In addition,based on analysis of the byproducts,the decomposition mechanism of chlorobenzene in the coupled reactor is also discussed.

Conversion of NO with a catalytic packedbed dielectric barrier discharge reactor

This paper discusses the conversion of nitric oxide（NO） with a low-temperature plasma induced by a catalytic packed-bed dielectric barrier discharge（DBD） reactor. Alumina oxide（Al2O3）,glass（SiO2） and zirconium oxide（ZrO2）, three different spherical packed materials of the same size, were each present in the DBD reactor. The NO conversion under varying input voltage and specific energy density, and the effects of catalysts（titanium dioxide（TiO2） and manganese oxide（Mn Ox） coated on Al2O3） on NO conversion were investigated. The experimental results showed that NO conversion was greatly enhanced in the presence of packed materials in the reactor, and the catalytic packed bed of Mn Ox/Al2O3 showed better performance than that of TiO2/Al2O3. The surface and crystal structures of the materials and catalysts were characterized through scanning electron microscopy analysis. The final products were clearly observed by a Fourier transform infrared spectrometer and provided a better understanding of NO conversion.

Decomposition of dioxin-like components in a DBD reactor combined with Hg/Ar electrodeless ultraviolet

A new combined reactor with Hg/Ar electrodeless ultraviolet(EDUV)activated by DBD for 3,4-dichlorodiphenyl ether abatement is presented.The effect of specific input energy and feeding gas component on 3,4-dichlorodiphenyl ether removal efficiency has been explored.Compared with a single DBD system,this new combined process performed a significant promotion on 3,4-dichlorodiphenyl ether abatement.Experiment results verified that active oxygen clearly contributed to the synergistic activity of DBD-EDUV system.Results of emission spectra showed that UV radiation of 253.7 nm could be detected in the DBD-EDUV system.Further,the products of DBD-EDUV process were analyzed via gas chromatographymass spectrometer(GC-MS)to reveal involved decomposition mechanism.

In situ electron-induced reduction of NOx via CNTs activated by DBD at low temperature

In this study,a new in situ electron-induced process is presented with carbon nanotubes(CNTs)as a reduction agent activated by dielectric barrier discharge(DBD)for nitrogen oxide(NOx)abatement at low temperature(<407 K).Compared with a single DBD system and a DBD system with activated carbon(DBD-AC),a DBD system with carbon nanotubes(DBD-CNT)showed a significant promotion of NOx removal efficiency and N2 selectivity.Although the 02 content was 10%,the NOv conversion and N2 selectivity in the DBD-CNT system still reached 64.9%and 81.9%at a specific input energy(SIE)of 1424 J^L,and these values decreased to 16.8%,31.9%and 43.2%,62.3%in the single DBD system and the DBD-AC system,respectively.X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM)were utilized to investigate surface changes in the CNTs after activation by DBD to explore the NO.t reduction abatement mechanism of this new process.Furthermore,the outlet gas components were also observed via Fourier transform infrared spectroscopy(FTIR)to help reveal the NOr reduction mechanism.Experimental results verified that carbon atoms excited by DBD and the structure of CNTs contributed to the synergistic activity of the DBD-CNT system.The new deNOx process was accomplished through in situ heterogenetic reduction reactions between the NOx and carbon atoms activated by the plasma on the CNTs.In addition,further results indicated that the new deNOv process exhibited acceptable S02 tolerance and water resistance.