Abstract: The electrocatalytic performance of the Ir catalyst prepared with a new complex reduction method using NH4F as the complexing reagent for the oxidation of ammonia was reported. The results indicated that the average size of Ir particles in the Ir catalyst prepared with the complex reduction method was 2.8 nm, which was much smaller than that (7.5 nm) of the Ir catalyst prepared with the reduction method without the complexing reagent, because Ir3+ could form the complex with NH4F. Thus, the electrocatalytic activity and stability of the Ir catalyst prepared with the complex reduction method for the oxidation of ammonia are better than that of the Ir catalyst prepared with the reduction method without the complexing reagent. This preparation method is very simple. Therefore, it is hopeful to have a practical application in the catalyst preparation.

Key words: Ir catalyst, Ammonia, Ammoniumfluoride, Complex reduction method, Amperometric ammonia sensor