A carbon dioxide monitor has been used to follow the Faradaic yield Of CO2 from the oxidation of ethanol vapour in a direct ethanol PEM fuel cell at ambient temperature. The time resolution of the CO2 measurements (ca. 15 s at half height for a burst Of CO2) was sufficient to observe stripping of adsorbed CO from the anode, and to monitor CO2 yields as a function of time during linear sweep and pulse experiments. It has been demonstrated that CO, yields can be increased dramatically by pulsing the potential or current such that adsorbed CO is stripped from the electrode and then ethanol is allowed to readsorb. Yields Of CO2 as high as 80% have been sustained for as long as 50 s under current pulsing conditions. An average CO2 yield of 45% was obtained during 600 s of pulsing the current between 0 and 4 mA cm(-2) at 1 Hz. (C) 2007 Elsevier B.V. All rights reserved.