Abstract: The present invention refers to a method of treating a platinum-alloy catalyst, comprising the steps of: A) providing a platinum-alloy catalyst, which comprises platinum (Pt) and at least one metal (M), which is less noble than platinum; B) exposing the catalyst to an acidic or basic medium, and exposing the catalyst to an adsorptive gas, wherein during step B) the catalyst is not subjected to an external electrical current or voltage. Further, the invention refers to a treated platinum-alloy catalyst. Moreover, and a device for carrying out the method of treating the platinum-alloy catalyst is provided.