Abstract: In this paper, the Ir catalysts supported on Vulcan XC-72 carbon(XC)(Ir/XC) and on the mixture of WC and Vulcan XC-72C(Ir-WC/XC) were prepared. Based on the characterizations with energy dispersive spectroscopy and X-ray diffraction patterns, the electrocatalytic performances of the two Ir catalysts on different supports for ammonia oxidation were investigated using the electrochemical techniques. It showed that the current density of the ammonia oxidation peak at the Ir-WC/XC catalyst electrode is 31.26% larger than that at the Ir/XC catalyst electrode. Furthermore, the electrocatalytic stability of the Ir-WC/XC catalyst is obviously better than that at the Ir/XC catalyst.

Key words: ammonia oxidation, tungsten carbide and Vulcan XC-72 carbon supported Ir catalyst, electrocatalytic performance, current type of electrochemical sensor