Protection of catalyst in fuel cell elec-trode

摘要

In addition to the oxidation catalyst a substance is added to the fuel electrode which can be reversibly oxidised at a potential lower than that at which irreversible damage to the catalyst occurs. For a mixed Mo4+, Mo5+ oxide catalyst this occurs at -750 mV when soluble Mo6+ is formed. The potential of the H2/H+ electrode is -928mV. Addition of cadmium gives the Cd right arrow Cd(OH)2 reaction at -900mV thus protecting the catalyst for a limited period of voltage rises due, for instance, to an interruption in the H2 supply.