PdRu films were successfully synthesized on top of non-porous stainless steel supports by electroless co-deposition. The effect of synthesis variables on morphology, substrate adherence, bulk and surface composition was studied. The microstructure and morphology of the samples were analyzed by X-ray diffraction and scanning electron microscopy. Homogeneous and defect-free PdRu films were obtained employing baths at low pH, moderate to high agitation speeds, high concentration of hydrazine, using EDTA as a stabilizer and temperatures near 50 degrees C. Films characterized by X-ray photoelectron spectroscopy showed Pd segregation after annealing the sample at 400 degrees C in H(2) (5%)/Ar in the load-lock chamber of the spectrometer. The optimized conditions were employed to synthesize a PdRu composite membrane on top of a tubular porous stainless steel substrate (0.1 mu m grade). Hydrogen permeation was measured over a 350-450 degrees C temperature range and a trans-membrane pressure up to 100 kPa. The PdRu membrane showed good performance with a hydrogen permeability of 6.5 x 10(-9) mol m(-1) s(-1) Pa-(0.5) and a selectivity higher than 1700. (C) 2011 Elsevier B.V. All rights reserved.