In this work, H-2 production via catalytic water gas shift reaction in a composite Pd membrane reactor prepared by the ELP "pore-plating" method has been carried out. A completely dense membrane with a Pd thickness of about 10.2 mu m over oxidized porous stainless steel support has been prepared. Firstly, permeation measurements with pure gases (H-2 and N-2) and mixtures (H-2 with N-2, CO or CO2) at four different temperatures (ranging from 350 to 450 degrees C) and trans-membrane pressure differences up to 2.5 bar have been carried out. The hydrogen permeance when feeding pure hydrogen is within the range 2.68-3.96.10(-4) mol m(-2) s(-1) Pa-0.5, while it decreases until 0.66-1.35.10(-4) mol m(-2) s(-1) Pa-0.5 for gas mixtures. Furthermore, the membrane has been also tested in a WGS membrane reactor packed with a commercial oxide Fe-Cr catalyst by using a typical methane reformer outlet (dry basis: 70%H-2-18%CO-12%CO2) and a stoichiometric H2O/CO ratio. The performance of the reactor was evaluated in terms of CO conversion at different temperatures (ranging from 350 degrees C to 400 degrees C) and trans-membrane pressures (from 2.0 to 3.0 bar), at fixed gas hourly space velocity (GHSV) of 5000 h(-1). At these conditions, the membrane maintained its integrity and the membrane reactor was able to achieve up to the 59% of CO conversion as compared with 32% of CO conversion reached with conventional packed-bed reactor at the same operating conditions. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.