Selective Catalytic Ammonia Oxidation into Nitrogen and Water Vapour

An increasing amount of ammonia slip affects DeNOx technology used to reduce nitrogen oxides emissions from power plants and other stationary sources of NOx emissions, heavy trucks, gasoline and Diesel passenger cars. The control and removal of ammonia emissions in waste streams are required. The process of the selective catalytic oxidation of ammonia into nitrogen and water vapour is one of the most promising methods for elimination of toxic ammonia from flue gases. As catalysts for the process hydrotalcite-derived mixed metal oxides were tested. The studies performed in the frame of the research were presented in four scientific papers (Catalysis Letters, Applied Catalysis B: Environmental, Journal of Thermal Analysis and Calorimetry, Chemik). Mixed metal oxides have been found to be active, selective to nitrogen and stable in ammonia oxidation. Their activity and selectivity strongly depend on chemical and phase composition and their redox properties. Optimum composition of the catalysts guaranteeing high catalytic performance was proposed. The internal SCR (i-SCR) mechanism was investigated for the reaction performed over the studied catalysts.