Preparation And Study Of Catalyst By Anodic Oxidation Treatment And Adding With The Rare Earth For Volatile Organic Compounds Oxidation

Nowadays, volatile organic compounds (VOCs) from chemical and petrochemical plants have given rise to comprehensive attention for their hazardous to the environment and human health. There are many different techniques used for elimination of VOCs. Among them, catalytic combustion is regarded as up-to-date feasible methods, for its high efficiency and no formation of by-products.Rare earth materials showed very excellent characters in the industrial exhaust gas. It was reported that the rare earth elements appeared as good associate catalysts, and they have excellent oxygen storage capacity. There are a lot of literatures focused on adding rare earth elements into noble or transition metal materials, on which showed good catalytic activity. In addition, the catalysts also showed good stability and good resistance.At first, we developed a noble metal catalyst, in which using stainless steel material as support by anodic oxidation treatment. We systematically investigated different conditions of anodic oxidation treatment, such as electrolyte concentrations and current intensity. At the same time, the influences of reductive time, calcined temperature and space velocity were also tested. The results indicated that 0.1%Pt-0.5%Pd/stainless steel wire mesh catalyst held the better catalytic performance for VOCs, on which the total conversion of toluene, acetone and ethyl acetate is at 220℃, 260℃and 280℃. The physical properties and surface structure of the catalysts were analyzed and characterized by SEM, XPS and EDX.On the basis of the results mentioned above, the study of introduce rare earth element of Ce was performed. The factors of Ce-Pt-Pd/stainless steel wire mesh catalyst for VOCs were also investigated, such as current intensity, reductive time, calcined temperature, and so on. Then the thermal stability and the catalytic activity of VOCs oxidation over the catalysts were tested. The results revealed that 0.75%CeO₂-0.1%Pt-0.5%Pd/stainless steel wire mesh catalyst had the best performance for VOCs, on which the total conversion of toluene, acetone and ethyl acetate is at 160℃, 220℃and 250℃, respectively. The structure and catalytic properties of the catalysts were investigated by means of SEM, XPS, TPR, EDX technologies.