Niobium oxide supported Pd-Co catalysts were characterized through XPS (X-ray photoelectron spectroscopy), (XPS), temperature-programmed reduction (TPR), magnetic measurements, X-ray diffraction, and extended X-ray absorption fine structure (EXAFS). XPS analyses suggested the presence of Co3O4 particles and Co2+ surface phase. TPR and magnetic measurements showed that the palladium addition promoted not only the reduction of Co3O4 particles but also the cobalt surface phase. Magnetic measurements and EXAFS analyses revealed the Pd-Co alloy formation during reduction. A model represented by bimetallic particles enriched with palladium and particles containing only cobalt was proposed.