Copper/Vanadia/Titania Bifunctional Catalysts for Ammonia Remediation

NH₃ is an important source of malodor associated with the transportation, processing and storage of organic and biological wastes. Power plants are also becoming an important source of NH₃ malodor, and new diesel engine vehicles fitted with SCR systems are potential non-point source of ammonia. Vanadium oxides can catalyze many partial oxidation reactions including that of alkane, olefins and alcohols, and more recently that of the selective catalytic oxidation of NH₃ to N₂. This study explores a series of bifunctional catalysts based on copper-vanadia supported on titania for catalytic remediation of NH₃ in air. Copper-vanadia on titania catalysts are more active than the vanadia catalysts for NH₃ oxidation at low to medium temperatures. Both bifunctional and vanadia-titania catalysts can convert NH₃ to N₂ at room temperature without NOx formation, however NOx formation in the bifunctional catalysts occurred above 100°C. This suggests a different reaction pathway is operative compared to the vanadia-titania catalyst.