Au/CeO2 catalysts shaped as nanofibers were obtained by supporting Au nanoparticles (ca. 3 nm) on CeO2 nanofibers of around 200 nm diameter. The CeO2 support was prepared by calcining electrospun polymer nanocomposite fibers with a high Ce content; then gold nanoparticles were either synthesized in situ or deposited from a suspension. The prepared catalysts were used in the preferential oxidation of CO in a hydrogen-rich stream. The catalysts prepared by deposition of preformed gold nanoparticles were less stable and underwent sintering due to a weaker nanoparticle-support interaction. In contrast, the catalysts with Au nanoparticles synthesized in situ were active (90% conversion and 46% selectivity) and stable. The fiber-shaped catalyst was able to give maximum reactant access at a much lower pressure drop than catalyst in powder form. (C) 2015 Elsevier Inc. All rights reserved.