Abstract:

The Ir-Co/C catalyst was prepared via a liquid phase reduction method. X-ray diffraction(XRD) and transmission electron microscope(TEM) results indicated that Co atoms enter the crystal lattice of Ir and form the Ir-Co alloy as evidenced by the lattice constriction of Ir and the aggregation of Ir particles could be suppressed. The electrochemical investigation illustrated that comparing with the Ir/C catalyst, the onset potential of the NH3 oxidation is negatively shifted about 100 mV, the peak current density is increased about 100% and the electrocatalytic stability is also increased at the Ir-Co/C catalyst. In addition, the sensitivity and the detection limit of NH3 are decreased at the Ir-Co/C catalyst. The results illustrate that the electrocatalytic performance of the Ir-Co/C catalyst for the NH3 oxidation is obviously better than that of the Ir/C catalyst. Thus, the Ir-Co/C catalyst has a potential application in the electrochemical NH3 sensor.

Key words: Carbon supported Ir-Co catalyst, Ammonia, Electrocatalytic performance, Current-type electrochemical NH3 Sensor