Preferential Oxidation of Carbon Monoxide in Hydrogen rich Streams (PROX)
Proton exchange membrane (PEM) fuel cell anodes are easily poisoned by small concentrations of carbon monoxide in their fuel. Currently, hydrogen is produced mostly from hydrocarbon sources using steam or autothermal reforming followed by low and high temperature water gas shift reactors.
The typical effluent from these reactors contains up to 2% carbon monoxide. To function properly, current PEM fuel cell anodes require less than 10 ppm carbon monoxide in their fuel. Preferential oxidation of carbon monoxide is a simple and effective method to clean hydrogen prior to introduction to the fuel cell anode. There are competing reactions that can occur when feeding hydrogen, oxygen and carbon monoxide into a catalytic reactor. The desired reaction is the oxidation of carbon monoxide while the major undesired reactions are methanation and H2 combustion. Our focus is on developing materials that can be both active and selective to the oxidation of carbon monoxide.