关键词: 镍电极, 氧析出反应, 稳态极化

Abstract: The steady_state polarization curves of oxygen evolution were measured at temperatures between 22～70 ℃ on Ni electrode in 30 wt.% KOH solution by galvanostat methode. The exchange current densities, Tafel slopes and transfer coefficients were studied. It was found that 40 ℃ is a special temperature, near which the kinetic parameters change abrupdy. The Tafel slopes for oxygen evolution reactions at higher overpotentials change from more than 120 mV to about 70 mV when the temperature raises to 40～70 ℃ from 22～35 ℃. Simultaneously, the heat of activation is changes from 79.88 kJ/mol to 55.32 kJ/mol. Moreover, the -(η/Τ) i and how it changes with lg i are quite different in the two temperature ranges: The slope of -(η/Τ) i vs. lg i is 4.63 at the lower temperatures, while at the higher temperatures it is only -0.455.