Research On Efficient Catalytic Oxidation Of Aromatic VOCs At Room Temperature

With the promulgation of laws and regulations about VOCs control in China,more and more attention has been paid to aromatic VOCs control technology,and the research on VOCs control technology has become a hotspots.The traditional aromatic VOCs treatment technology such as incineration and catalytic incineration need high temperature condition,high treatment cost and high risk coefficient.The catalytic oxidation of aromatic VOCs at room temperature has great development potential and prospect in the VOCs control due to its mild reaction conditions and high safety factor.Therefore,it is of great significance to study the catalytic oxidation VOCs at normal temperature.The Pt/TiO₂,Au/TiO₂,Pd/TiO₂,Ag/TiO₂,Pt/CeO₂,Pt/La₂O₃,Pt/hydroxyapatite catalysts were prepared.The catalytic oxidation degradation of toluene,one of the representative compounds of aromatic VOCs,was carried out at room temperature,and the degradation effect of toluene was evaluated.The results showed that the Pt/TiO₂ catalyst has the highest catalytic degradation rate for toluene.Furthermore,the preparation process of Pt/TiO₂ catalyst was optimized,and the influence of the calcination temperature and the loading rate on the catalytic performance of the catalyst was investigated.The results showed that the catalyst activity is the highest when the calcination temperature was 400?,and the loading rate of Pt/TiO₂ was 1%.The catalytic ozonation reaction conditions were explored.When the reaction temperature was 25?,the ozone concentration was 2600 mg/m³,the initial concentration of toluene was 250 mg/m³,and the space velocity range was 60000-30000 h^-1,the highest degradation rate of toluene by Pt/TiO₂ to toluene is 65%.The kinetics of the catalytic ozonation toluene by Pt/TiO₂ was studied,and the activation energy of the catalytic oxidation of toluene at room temperature was 47 KJ·mol^-1.In this paper,the prepared Pt/TiO₂ catalysts were characterized by SEM,ICP,BET,XPS and XRD.The results of SEM showed that the particles of the catalyst were dispersed uniformly and exhibited high catalytic activity.The determination of XPS showed that the active component Pt of the Pt/TiO₂ catalyst exists mainly in the form of+4 valence and 0 valence.The results of BET showed that the catalyst Pt/TiO₂is mainly mesoporous structure and the pore size distribution was even.XRD characterization showed that the main components were anatase and Pt which exists on the TiO₂ was smaller grains and high dispersion.Infrared characterization results showed that the ethers and esters were generated in the catalyst after reaction.