Study On The Performance And Mechanism Of Bimetallic Supported Catalyst For Catalytic Oxidation Of Volatile Organic Compounds In Coal-fired Flue Gas

Coal-burning processes consume a large number of coal resources while discharging a wide variety of pollutants,including dust,particle matter（PM）,NO_x,SO₂and other conventional pollutants.At the same time,the process also produces volatile organic compounds（VOCs）,its perniciousness cannot be ignored.In this work,a close-coupled catalytic oxidation module had been built,which had catalytic materials as the core,after the NH₃-SCR process section to achieve high-efficiency oxidation of toluene during coal-fired flue gas purification.The V-Cu bimetal oxide supported catalyst,which not only can efficiently remove VOCs but also have high resistance to complex flue gas,was facilely fabricated by a simple and industrially operable impregnation method.The V-Cu bimetallic bifunctional catalyst supported on ZSM-5 zeolite（V-Cu/ZSM-5）was facilely fabricated via the incipient wetness impregnation method.Compared with the single metal oxide-supported catalyst,V-Cu/ZSM-5 showed an excellent catalytic performance.The superior performance was attributed to more excellent low-temperature reducibility,more acid sites,higher electron transfer efficiency,more abundant Oαspecies and lower C₇H₈ activation temperature.In addition,the material exhibited excellent flue-gas tolerance and CO_x selectivity,whereas there is strong competitive adsorption between NH₃/NO and toluene,besides,SO₂ could cause chemical poisoning of the catalyst.Finally,in-situ DRITFS technology was carried out to reveal the reaction mechanism.In view of the complexity of real coal-fired flue gas,a V-Cu bimetal oxide supported catalyst that was more suitable for industrial applications was designed.Compared with ZSM-5,Si O₂ andγ-Al₂O₃,V-Cu/Ti O₂ catalyst has the best catalytic performance,which is due to its excellent redox properties,abundant acid sites and oxygen vacancies,which in turn promotes the strong interaction between active components and supports.The catalyst can have high activity,high resistance and high stability in coal-fired flue gas with wide concentration fluctuations and high space velocity.At the same time,V-Cu/Ti O₂ catalyst has good degradation efficiency for toluene,propene,dichloromethane and other multi-component VOCs.This work provides new ideas and technologies for building and developing NO_x and VOCs treatment system in the complex coal-fired flue gas.