Study On Efficient Non-thermal Plasma Degradation Of Toluene Over NiO/?-Al₂O₃ Catalyst

VOCs are important air pollutants,which have great harm to human body and environment.Compared with traditional VOCs treatment technologies,such as combustion,absorption and condensation,non-thermal plasma technology has the characteristics of low energy consumption,high efficiency and easy operation.It is a research hotspot in organic waste gas treatment technology.In this paper,the removal of toluene in the catalytic degradation system by non-thermal plasma combined with dielectric barrier discharge reactor was studied.The prepared catalysts were physico-chemical characterized.Firstly,the effects of inlet concentration of toluene,space velocity and background gas on toluene removal were investigated in a single DBD reactor.Under the same other conditions,the removal of toluene decreases with the increase of toluene inlet concentration and space velocity.Secondly,NiO/?-Al2O3 catalysts with different NiO loadings were prepared by impregnation method.The effects of SIE,catalyst calcination temperature and NiO loadings on toluene degradation were investigated.The catalyst prepared by calcination at 450? has the highest activity.The catalytic activity of catalysts increases first and then decreases with the increase of NiO loading and the maximum toluene conversion of 93%was achieved used 1.25 wt%NiO/?-Al2O3 at 200 ppm.Meanwhile,only a small amount of nitrogen oxides is produced in the process of non-thermal plasma catalytic reaction using NiO/?-Al2O3 catalysts.Finally,La-NiO?-Al2O3 catalysts with different La loadings were prepared and their activity was tested under the same conditions.The results show that the addition of appropriate La promoter can effectively enhance the catalytic activity.When La loading is 0.3 wt%,gas inlet concentration is 200 ppm and SIE is 3.7 kJ/L,toluene removal can reach about 99%.