The results of electrochemical studies carried out on W-x(CO)(n) electrocatalyst are presented in this article. W-x(CO)(n) was synthesized from W(CO)(6) in xylene at 140 degreesC. The kinetic studies were carried out in 0.5 M H2SO4 solution under a three-electrode configuration. Linear voltametry studies on W-x(CO)(n) reveal significant catalytic activity of the material for oxygen reduction. Koutecky-Levich analysis of the voltametry data shows that the reaction follows first-order kinetics and the value of the Koutecky-Levich slope indicates a multi-electron charge transfer in the oxygen reduction reaction. The value of Tafel slope is Found to be -120 mV/decade from the mass-transfer-corrected Tafel plots. The charge transfer coefficient and exchange current density were found to be 0.66 and 8.4 x 10(-5) A/cm(2), respectively. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.