A series of aiuminumphosphate molecular sieves supported platinum-cobalt catalysts were prepared and tested for the preferential oxidation of CO in H-2-rich gases. The catalysts were characterized by XRD, HRTEM, EDX, TPR and XPS techniques. The optimized catalysts were highly active and selective, CO could be purified below 10 ppm in the reaction temperature range of 110 degrees C-125 degrees C under 1% CO, 1% O-2, 12.5% CO2, 15% H2O, 50% H-2 in volume and N-2 balance at the space velocity of 24,000 mL g(cat)(-1) h(-1). Pt-Co/CoAPO-5 exhibited the best catalytic performance and Pt-Co/AlPO-5 was the most active catalyst at low reaction temperature, in which particles of Pt-Co alloy were formed and the particles were highly dispersed on the surface of the support. The high activity could be attributed to the Pt-Co nano-partilces with small sizes. The enlarged temperature window for CO purification should be ascribed to the loaded cobalt oxide. Substitution of cobalt ions for aluminium ions has obvious influence on the interaction between the support and platinum/cobalt species. (C) 2013 Elsevier B.V. All rights reserved.