CATALYTIC REDUCTION OF NO OVER PEROVSKITE-TYPE CATALYSTS

In the present work, we have investigated the reduction of NO by propa ne over perovskite-type oxides prepared by malic acid method. The cata lysts were modified to enhance the activity by substitution of metal i nto A or B site of perovskite oxides. In addition, the reaction condit ions, such as temperature, O-2 concentration, and space velocity have been varied to understand their effects on the catalytic performance. In the LaCoO3 type catalyst, the partial substitution of Ba and Sr int o A site enhanced the catalytic activity in the reduction of NO. For t he La0.6Ba(Sr)(0.4)Co1-xFexO3 (x=0-1.0) catalyst, the partial substitu tion of Fe into B site enhanced the conversion of NO, but excess amoun t of Fe decreased the conversion of NO. The surface area and catalytic activity of perovskite catalysts prepared by malic acid method showed higher values than those of solid reaction method. The conversion of NO increased with increasing O-2 concentration and contact time. The i ntroduction of water into reactant feed decreased the catalytic activi ty but the deactivation was shown to be reversible over La0.6Ba0.4Co1- xFexO3 catalyst.