Study On Catalytic Oxidative Degradation Of Nitrobenzene By Self-made Cu/Co Composite Catalyst

In recent years,China,as a developing country,has been developing in an orderly manner,and science and technology have gradually matured.In some important production processes,a large number of organic raw materials are applied,which not only increases productivity but also results in the production of large areas of organic pollutants.Among them,nitrobenzene?NB?,as a common chemical material,still shows its inherent high toxicity even at low concentrations,which brings higher dangers to the ecological environment and human well-being.The removal of organic pollutants has not only attracted attention in China,but also attracted more and more scholars from other parts of the world.This work is intended to quickly and effectively degrade NB.In the catalyst preparation experiment,a copper-cobalt bimetal catalyst?Cu/Co?that can effectively activate H₂O₂was prepared by a hydrothermal method.The amount of precursors,the hydrothermal time,and the hydrothermal temperature were studied by changing related factors.Influence of catalyst pretreatment with or without ultrasonic pretreatment and propionaldehyde addition.XPS,TEM,FTIR-ATR,nitrogen isothermal adsorption/desorption,and XRD were used to characterize the catalyst,and the oxidation of the catalyst was explored.The relationship between performance and microstructure results in the optimal preparation conditions.In the experimental process of oxidative degradation of NB in a multi-phase Fenton system,the effects of different factors on the degradation of NB were explored and the optimal reaction conditions for oxidative degradation were proposed.In tert-butanol quenching free radical experiments and benzoic acid probe experiments,the main active oxidizing substances in the degradation process of NB were studied.In the continuous degradation NB experiment and catalyst metal dissolution experiment,the chemical stability of the prepared catalyst was studied.The results show that the synthesized Cu/Co catalyst has the best catalytic activity.When the reaction precursor dosage ratio is 1:1,the hydrothermal time is 48h,the hydrothermal temperature is 200?,and the ultrasonic pretreatment is carried out under conditions of propionaldehyde addition.During the degradation of NB,Cu/Co has significant catalytic activity for H₂O₂and can rapidly and efficiently degrade NB over a wide p H range?3-9?.The optimum degradation reaction conditions are:when the Cu/Co catalyst dosage is 2.5g/L,the H₂O₂dosage is 0.8mol/L,the initial p H=7,and the room temperature under normal light conditions,10mg/L NB?about 81?m?can be 100%degraded within 45 min.And this degradation process follows the mechanism of hydroxyl radicals and is an interfacial microscopic reaction.The Cu/Co catalyst synthesized after four consecutive degradations of NB still has good chemical stability.The oxidative degradation rate of nitrobenzene can still reach 100%under the same conditions,after 60 minutes of the fourth catalyst reaction.The dissolution rates of Cu and Co metals were 0.00035%and 0.56%,respectively,indicating that the content of Cu and Co in the synthesized Cu/Co catalyst was 14.48%/g and 14.79%/g,which had a relatively high metal content.It can be seen that the Cu/Co catalyst has good chemical stability,and the good catalytic activity and stability also greatly improve the practical potential of Cu/Co as a multiphase Fenton catalyst.