The Research Of Pluse Discharge Plasma Combined With Perovskite Catalysts Removal Of Nitrogen Oxides

As the main pollutant in the atmosphere,NOx is harmful to the environment and human health,so the control of the NOx emissions from motor vehicles is a hot research topic and the removal of NOx.which has very important practical significance and application value.High voltage pulse discharge plasma collaborative catalyst is one of the most promising methods to remove NOx,but there are two major problems,such as consumption of high energy and difficult to control by-products,so the preparation of high efficiency catalysts is the key to solve the problem.In this paper,nitrogen oxides as treated pollutants,the effect of electrode configuration on pulse discharge energy and the rate of NO conversion,and NOx removal under aerobic and anaerobic conditions were studied by using a self-made wire-tube pulsed discharge reactor with perovskite catalysts,At the same time,LaMnO₃ perovskite catalysts were prepared by citric acid sol-gel method,doped Fe,Co,Ni,Sr,Ce and other elements.By changing the content ratio between the elements,the addition of citric acid,the roasting temperature of catalysts,the temperature of NOx gas and the content of catalyst in the reactor.The effects of NO conversion,NO₂ production and NOx removal were studied to improve the removal rate of nitrogen oxides and reduce energy consumption,control by-product output.At the same time,the catalysts were characterized by XRD,SEM,XPS and BET,and the relationship between the micro-morphology,structure,active substance and catalytic property of the catalysts were studied.The following research results are obtained:?1?When the diameter of the high voltage pole is 4 mm and stainless steel tube is 53 mm,the effective current and the single pulse energy were higher than the others.Compared with the straight bar,the current and single pulse energy of thread rod were significantly larger than that of the straight rods.?2?The LaMn_1-x-x Fe_xO₃ was doped by Fe element,which can improve the rate of NO conversion and NO₂.When the Fe addition amount was 0.3,the citric acid and the metal cation ratio was 1:1 and the roasting temperature was 700?,the LaMn_0.7Fe_0.3O₃ catalyst relative content of lattice oxygen and adsorption oxygen has changed,and the morphology,specific surface area,has the best efficiency.Which the optimal additive quantity of the catalyst is 1.6g.and optimum gas temperature was 300?,NO conversion rate 93.96%,NOx removal rate was 62.15%.?3?The effect of NO conversion and NOx removal by catalysts with B-bit doped Co,Ni were studied.When Ni doping quantity was 0.2 and the voltage was 30kV,the conversion rate of NO was reached 89.06%.The NOx removal rate increased from 62.15%to 63.66%.was superior to the LaMn_0.5Co_0.2Fe_0.3O₃ catalyst to the NOx removal rate 62.25%.?4?The LaMn_0.5Ni_0.2Fe_0.3O₃ of the catalyst were doped Sr and Ce elements,when the doping quantity was 0.3 and the voltage was 30kV,the catalyst had the highest conversion rate of NO,and conversion rate reached 92.81%,NOx removal rate from 63.66%to 73.51%.increased by 9.52%.La_0.5Ce_0.2Sr_0.3Mn_0.5Ni_0.2Fe_0.3O₃ catalyst A was doped Ce element,when the doping quantity of Ce was 0.2,the catalyst has has fine particle size and specific surface area.the highest NOx removal rate and NOx removal rate was 81.31%.