A system and method for determining a maximum average cell voltage set-point for fuel cells in a fuel cell stack that considers oxidation of the catalyst in the fuel cells. The method includes determining the average cell voltage, the stack current density (I) and an internal resistance (R) of membranes in the fuel cells to calculate an IR corrected average cell voltage. The IR corrected average cell voltage is then used to determine the oxidation state of the catalyst particles using, for example, an empirical model. The oxidation state of the particles is then used to calculate the maximum average cell voltage set-point of the fuel cells, which is used to set the minimum power requested from the fuel cell stack.