Selective CO oxidation over Pt/alumina catalysts for fuel cell applications

It has been demonstrated that even traces of CO present in the hydrogen rich feed gas to proton exchange membrane (PEM) fuel cells can poison the platinum anode electrode and dramatically reduce the power output. The tolerable level of CO is around 10ppm. In this paper, we present the results of selective CO oxidation in simulated reformate gas over single-step sol-gel prepared Pt/alumina catalysts. The effect of water vapor, carbon dioxide, CO and oxygen concentrations, temperature, and Pt loading on the activity and selectivity are presented. Our results show that a 2% Pt/alumina sol-gel catalyst can selectively oxidize CO down to a few ppm with constant selectivity and high space velocity. Water vapor in the feed increases the activity of the catalysts dramatically and in the absence of water vapor, CO2 in the feed stream decreases the activity of the catalysts significantly. (C) 2002 Elsevier Science B.V. All rights reserved.