The on-site production of hydrogen from liquid alcohols and hydrocarbons is the most practical option for PEM fuel cell applications, since the storage and transportation of H₂ fuel at this time is impractical. However, CO present in the reformate poisons platinum electro-catalyst. Thus, preferential oxidation (PrOx) is used which uses a Pt based catalyst to selectively oxidize CO. Despite being universally adopted in fuel reformers, the current PrOx technology used to reduce the CO is in fact, cumbersome and bulky. Another limitation is the poor selectivity of the PrOx reactor for CO oxidation over H₂. An entirely novel approach involving electrochemical preferential oxidation (ECPrOx) is being developed in our laboratory which exploits the oscillatory CO electro-oxidation by utilizing electric potential to cleanse CO from reformate using a device similar to PEM fuel cell in structure. Here selective CO electro-oxidation is achieved at the anode by rendering the process electrochemical. In addition, supplemental power is produced with no H₂ wasted. The presentation elucidates the effect of operating temperature, operating pressure, feed CO concentration and humidification, for an anode consisting of pure Ru. The ECPrOx can be operated at near room temperature, high anode pressure, atmospheric air breathing and without external humidification. Conversions as high as 95% are achieved up to 500 ppm CO, however for higher CO concentrations (1000 ppm) the conversion decreases on pure Ru. Furthermore, system performance drops after about 400 hours with pure Ru as the anode catalyst. A binary electrode structure or PtRu is found to be an effective alternative to pure Ru at the anode. The mechanism of ECPrOx to selectively oxidize CO will also be briefly discussed in the presentation.