Effects of temperature on the performance of Cu-Ni oxygen anodes in alkaline solution

摘要

Potentiodynamic polarization curves were generated for Cu-Ni activated electrodes by using a very slow scan at 0.05 mV/s in the region of oxygen evolution at 50, 60, 70 and 80 deg C. Activation was performed by electrochemical oxidation at a current density of 1.3 A/cm~2 by potentiostatic polarization at 1.5 V(Hg/HgO) for 100 hrs in 6M KOH solution kept at 50 deg C. From the data analysis it was found that an increase in temperature of the electrolte caused a significant lowering of the overpotential in the range from 152 to 260 mV at 100 mA/cm~2. Alloys with high Cu contents CN706 had to bes kinetic performance for OER in the low currents regions as compared with the other alloys tested (TSafel slope of 59 mV/dc). In the high currents region alloy with CN715 showed a better performance for lower Tafel slope, 102 mV/dc; while alloy CN706 showed a better performance for lower overpotential, eta , for OER, 306 mV.