The aim of this work is to employ niobium oxynitride with macropores generation-in the hydrazine decomposition reaction as substitute of iridium supported catalysts used for space communication satellites, which are equipped with microthrusters that control their orbit and attitude. The performance of niobium oxynitride was compared to tungsten oxynitride and Shell 405 catalyst. (C)2000 Elsevier Science B.V. All rights reserved.