Abstract
Catalytic combustion of the volatile organic compounds (VOCs) has an advantage of low oxidation temperature, which leads to low energy consumption. It is widely applied into industry. A novel preparing technology of Pt/Al2O3/Al catalyst for VOCs' catalytic combustion was presented in this paper. Al2O3 film was formed on aluminum plate by anodic oxidation in oxalic acid solution at current density of 50 A/m2. After the anodic oxidation, platinum was supported on the oxidized plate in aqueous solution of chloroplatinic acid hexahydrate via the electrolysis supporting method with alternating current in several minutes. Platinum loading of the developed catalysts was about 0.3 wt% and dispersion was about 50%. It indicated that platinum can be deposited on the anodized aluminum film. Through the respective combustion of benzene and toluene, activity of catalyst was evaluated. Above 90% conversion was obtained at 523 K in combustion system with space velocity of 20,000 h-1and VOC concentration of 1000 ppm.
Comparison with the impregnation method was also carried out. The results indicated catalyst prepared by the electrolysis supporting method has higher activity than that prepared by the traditional impregnation method, although the former has a lower platinum loading. In this paper, reasons for this high activity were also discussed from platinum dispersion, surface characters and so on. It can be concluded that the electrolysis supporting method share advantages of short time, high-activity and no use of NH3.
