Catalytic Oxidation Of Chlorinated Volatile Organic Compounds Over Ruthenium-based Catalysts

Chlorinated volatile organic compounds(CVOCs)widely exist in many industries such as chlor-alkali industry,petrochemical,pharmaceutical and pesticide,paint decoration and packaging and printing.Compared with other types of VOCs,they have more emissions,more toxicity,and they are more difficult to remove.The catalytic oxidation method has many advantages,such as low ignition temperature and high purification efficiency,whereas the polychlorinated by-products are usually generated in the catalytic oxidation of CVOCs,and the emission risk is accordingly increased.There are few systematic studies on chlorine migration mechanism at present catalytic systems.Therefore,it is very important to research the mechanism of chlorine migration and control the generation of polychlorinated by-products.In addition,the current stage on the catalytic oxidation of CVOCs over Ru-based catalysts is still in the laboratory scale research,and there are few domestic related studies on scale-up experiments.Therefore,it is innovative and promising to carry out the amplification test of CVOCs catalytic oxidation over Ru-based catalysts.In this paper,Pd/TiO2,Pt/TiO2,Ru/TiO2 and Rh/TiO2 catalysts were parpered using impregnation method to evaluate their catalytic performance for the catalytic oxidation of chlorobenzene,and the distribution and reaction mechanism of polychlorinated by-products.Then,the formation of PCBs by-products was analyzed and compared over Ru-and Pd-based catalysts.After that,the catalytic mechanism was proposed during the catalytic oxidation of chlorobenzene over each catalytic system.Furthermore,the independently designed VOCs catalytic oxidation test platform was used to inverstigate the influence of different chlorobenzene concentrations and different airspeeds on the catalytic reaction,and the tolerance test of the homemade Ru/Al/TiO2/cordierite monolithic catalyst was carried out.In this article,main innovations are as follows:(1)The catalytic performance of different catalytic systems was studied,including catalytic activity,stability,and selectivity.Especially,focusing on the generation and distribution of polychlorinated benzene and polychlorinated biphenyls in complex reactions.(2)By comparing and analyzing the chlorine migration mechanism during the catalytic reaction,the gradient conversion mechanism of CVOCs-polychlorobenzenepolychlorinated biphenyls was revealed,(3)In order to confirme the optimal reaction conditions,the effect of different process parameters were examined over monolithic Ru-based catalysts for the catalytic oxidation of chlorobenzene.