Preparation of Platinum Catalysts Supported on Anodized Aluminum for VOC Catalytic Combustion: The Effect of Supporting Method

摘要

Catalytic combustion of volatile organic compounds (VOCs) has a low oxidation temperature,which leads to low energy consumption.It is widely used in industry.A novel technology for preparing Pl/Al_2O_3/Al catalysts for catalytic combustion of VOCs is presented here.An A1_2O_3 film was formed on an aluminum plate by anodic oxidation in an oxalic acid solution at a current density of 50 A centre dot m~(-2).After the anodic oxidation,platinum was supported on the oxidized plate by the electrolysis supporting method with alternating current,in several minutes.The platinum loading of developed catalysts was about 0.3 wt% and the dispersion was about 50%.This indicated that platinum can be deposited on the ano-dized aluminum film.The activity of the catalyst was evaluated through the combustion of benzene and toluene.Above 90% conversion was obtained at 523 K in a combustion system with a space velocity of 40000 l centre dot h~(-1) centre dot m~(-2) and a VOC concentration of 1000 ppm.Comparison with the traditional impregnation method was also carried out.Research shows that catalysts prepared using the electrolysis supporting method have lower platinum loadings and higher metal dispersion than those prepared by the traditional impregnation method.In this paper,the supporting method effect was concluded to be an "embedding effect",by TPD and TPR analyses.Based on this study,it can be concluded that the electrolysis supporting method has the advantages of a short time requirement,high activity and no use of ammonia,compared with the impregnation method.It can be regarded as a novel technology for preparing catalysts.