Preparation And Characterization Of A New Material Adding With The Rare Earths For Volatile Organic Compounds Oxidation

With the improvement of industry, people have paid more attention to the environment, especially in the industrial exhaust gas. Rare earth catalytic materials have showed very excellent character in this field. It was reported that the rare earths were good associate catalysts, and they have excellent oxygen storage capacity. There are a lot of literatures focused on adding the rare earths element (Ce, Pr, La) into novel or transition metal materials, on which showed good catalytic activity. In addition, the catalysts have a good stability and good resistance.At the first of the paper, we illustrate the increasing deteriorated environment problems caused by the emissions of volatile organic compounds (VOCs) and different technologies of controlling the VOCs at present and the exiting problems. Among them, catalytic combustion is one of the most efficiency methods, which offers an advantage to eliminate VOCs, for instance high oxidation efficiency and low emission of unburnt hydrocarbon. Meanwhile, zirconium pillared montmorillonite materials and the rare earth oxide catalysts have been attracted more and more attention.In our study, a new material of zirconium pillared montmorillonite adding with the rare earth element was prepared. Two different methods were used to compare the difference. The structure and catalytic properties of the materials were investigated by means of TG-DTA, XRD, TEM, N₂ adsorption-desorption, TPR, IR and so on. The catalytic activity of samples for VOCs (included acetone, ethyl acetate and toluene) oxide reaction was investigated. It was found that the sample prepared by wet impregnation method had a better catalytic activity than the other one. After select out the best ratio of rare earth to Zirconium (1:8 mole ratios), catalysts supported with Pd, Cu and Mn were prepared by wet impregnation. Then the thermal stability and the catalytic activity of VOCs oxidation over the catalysts with various Pd, Cu and Mn content were investigated. Surface properties of the catalysts were investigated by means of TEM,TPR,N₂ adsorption-desorption and EDX methods. The results showed Cu and Mn catalysts supported on the zirconium pillared and Ce adding montmorillonite have the better catalytic activity than novel catalysts supported with Pd or Pt in our experiment.