The selective oxidation of ammonia using copper-based catalysts: The effects of water

The activity of copper oxide supported on alumina (3.4Cu/Al2O3) and a copper exchanged beta zeolite (3.0Cu/beta) for the selective oxidation of ammonia into nitrogen is presented. Both catalysts are active for the oxidation of ammonia into nitrogen and water, although the 3.0Cu/beta outperforms its alumina-based counterpart in terms of activity and selectivity to nitrogen. The activity of both catalysts decreases in the presence of water vapour. In the case of the copper supported on alumina catalyst, the activity could be restored by removal of water from the reactant stream. However, exposure of 3.0Cu/beta catalyst to extended use in the presence of water vapour irreversibly altered the catalyst and the initial high activity could not be restored.