A AuLa2(OH)(9) coprecipitate calcined in air at temperatures below 450 K showed surprisingly high catalytic activity for CO oxidation, 100% conversion at a temperature as low as 193 K, when it was reduced in a N-2 stream containing H-2 or CO at 373 K. The reduction treatment transformed Au(OH)(3) species interacting with the La(OH)(3) support into Au-0 clusters smaller than 1.8 nm in diameters. (C) 2010 Elsevier B. V. All rights reserved.