0.1%Pt-0.02%Pd/Stainless Steel Monolith Catalyst:Catalytic Oxidation of Acetone and Thermal Stability

Stainless steel monolith was chosen as catalyst support to overcome the drawbacks of poor thermal stability with catalysts using traditional γ-Al2O3 and cordierite honeycomb as the substrate. During the catalyst preparation process,anodic oxidation technique was used to produce a porous membrane over the support surface,leading to effective dispersion of platinum and palladium on stainless steel monolith. The results show that the temperature for the total oxidation of acetone is 160,160 and 200 ℃,respectively,with the catalyst calcined at 500,800 and 1 000 ℃. The role of porous membrane over the stainless steel monolith surface is important for fixing active components of platinum and palladium particles,which leads to the enhanced catalytic activity for total acetone oxidation. This 0.1% Pt-0.02% Pd/stainless steel monolith catalyst exhibits the following advantages:a) high temperature stability in the whole temperature range investigated(500～1 000 ℃),b) better catalytic activity than those platinum and palladium supported catalysts over γ-Al2O3 and cordierite honeycomb support previously reported,c) low metal loading of platinum and palladium components (0.1wt% Pt and 0.02wt% Pd). The microstructures,surface dispersion condition of platinum and palladium active components were studied by means of scanning electron microscopy(SEM) and energy-dispersive X-ray spectroscopy(EDX).