Selective catalytic oxidation of CO in H-2: Fuel cell applications

An essential requirement for the proton exchange membrane (PEN) fuel cell i s to deliver clean H-2 to the anode electrode, the kinetics of which are gr eatly hindered by traces of CO present from the upstream hydrocarbon steam reforming and water-gas shift processes. A technology receiving much attent ion is the selective oxidation of CO to CO2. Ideally the catalyst must sele ctively oxidize about 1% (10 000 ppm) CO to less than 5 ppm without oxidizi ng any of the 30-70% H-2 present. This paper describes performance results of a Pt promoted catalyst deposited on a monolith for selective oxidation o f CO under simulated fuel processing conditions for PEM fuel cell applicati ons. The effect of space velocity, gas composition and temperature on activ ity and selectivity is presented. Preliminary mechanism ideas are also pres ented. (C) 2000 Elsevier Science B.V. All rights reserved.