Study On The Removal Of Volatile Organic Compounds Containing In Cooking Fumes By Compound Mixed Catalysis

Volatile organic compounds(VOCs)are main urban air pollution sources which not only contaminate the environment but also threaten our health.Therefore,eliminating VOCs is of great significance nowadays.With the advantages of low price and good thermal stability,composite metal oxides have attracted much attention in the field of catalytic purification of organic pollutants.In this paper,hexanaldehyde,acetone and toluene were used as fume simulators to select zeolite-supported catalysts,oxide-supported catalysts and structure-type perovskite oxide catalysts for catalytic combustion of fume.Through comparative analysis,the research results show as follow:Compared with molecular sieve supported catalysts,LaMnO3 perovskite structure catalysts have better catalytic performance for treating hexanaldehyde.The catalytic performance was further improved by A and B modification.In particular,La0.8K0.2MnO3 has the best modification effect.When the doping of K makes it produce more Mn4+,generating a large amount of surface adsorbed oxygen which can promote the catalysis process of hexaldehyde,and T90 is only 120℃.By comparison,it was found that the acetone catalytic effect of manganese cobalt perovskite was better than that of the precious-metal(Pt,Pd)loaded γ-Al2O3,and the catalytic activity of LaMnO3 was better than that of LaCoO3.Further study found that Mn soaked LaCoO3 had better acetone catalytic activity than LaCo0.6Mn0.4O3(S-G)and MnO2/LaCoO3(DP),where the acetone conversion reached 94.67%at 210℃.Based on the great catalytic effect of perovskite on hexanaldehyde and acetone,the influence of the presence form of manganocoba perovskite and Pd ion on the catalytic activity of toluene was investigated.It was found that for volatile organic toluene,the catalytic activity of LaCoO3 was better than that of LaMnO3,and the catalytic activity of LaCo0.8Mn0.2O3 doped with Mn ion was the best,when T50 was 230℃ and T90 was 280℃.The loading of Pd slightly improved the catalysis effect for toluene,but compared with LaCo0.8Mn0.2O3,the modification effect is poor,T90=290℃,which fails to reflect the superiority of precious metals in organic matter catalysis.In a word,perovskite shows good catalytic performance of oil fume,while precious metals fail to exert their good performance in organic catalysis.