The focus of the present work is on the analysis of CO selective oxidation using catalytic zeolite (Pt/Na-Y) membranes in a continuous flow membrane reactor. A series of membranes with different permeation properties, prepared by secondary growth, Pt-loaded by ion exchange and reduced was used for this study. Catalytic tests were carried out with a simulated dry reformate shifted gas mixture with an operative O-2/CO stoichiometric equivalent feed ratio of two, at a temperature of 200-220 degrees C and reaction pressure up to 600 kPa. The best performance was achieved by the lowest permeance membrane considered in this work that showed also stable catalytic activity over many hours of testing. The catalytic membranes effectively reduced the CO content from 10,000 ppm down to 10-50 ppm, depending on the operating conditions. (c) 2008 Elsevier B.V. All rights reserved.