Gold nanoparticles were supported on activated carbon fibers (ACF) using the aq. soln. of [Au(en)2]Cl3 via ion-exchange with surface hydroxyl groups followed by redn. in H2. The obtained catalysts were tested in CO oxidn. at room temp. Surface phenolic groups fix Au3+-ions leading to the formation of small Au particles (.apprx.5 nm) after the redn. with high activity in the reaction. AAS, TPD, HRTEM/EDAX and XPS were used for characterization of the catalysts and supports.