A steady-state method for determining the dealloying critical potential

We show that the commonly accepted measurement of the critical potential for alloy dissolution calculated based on extrapolation of anodic polarization data results in an overestimation of this quantity. A series of constant applied potential experiments prove to be a more accurate method for critical potential determination. For the system Ag0.7Au0.3 in 0.1 M HClO4, we find that the true critical potential lies between 0.990-1.020 V vs. normal hydrogen electrode. This is approximately 115 mV below that conventionally determined by anodic polarization data. (C) 2003 The Electrochemical Society.