A novel membrane-based catalytic electrode was prepared by electrodepositing platinum, or an alloy of platinum and ruthenium, on pretreated zirconia-alumina substrates. The membrane substrates were carbonized or gold-sputtered in order to make them electron-conductive prior to electrodeposition. The catalytic oxidation of ethanol on the membrane-based electrodes was investigated and the electrodes were characterized by SEM and EDX. These novel electrodes showed high activity for the oxidation of ethanol. The addition of tungsten and molybdenum. especially as tungstosilicic acid or silicomolybdic acid, improved the activity of the electrode significantly. The addition of ruthenium depressed activity but may improve the durability of the electrode because of its ability to prevent poisoning with carbon monoxide. The high surface area of novel electrodes due to nano-sized catalytic particles and the characteristics of the variable valence of tungsten and molybdenum may be the main reasons for the high activity obtained. (C) 2003 Elsevier B.V. All rights reserved.