Palladium-iridium catalysts with different proportions between the metals and supported on a dealuminated Y zeolite (SAR similar to 26) had their activity and selectivity measured in tetralin hydrogenation at 523 K and 4 MPa. Characterization of the zeolite support showed that it was free from extra-framework alumina. A palladium-platinum catalyst supported on the same zeolite was also tested for comparison. The metal catalysts were characterized with respect to dispersion by hydrogen and carbon monoxide chemisorption. All of the catalysts displayed moderate deactivation during tetralin hydrogenation and only cis- and trans-decalin were observed as reaction products. For the same proportion between the metals and the same zeolite support, Pd-Pt and Pd-Ir catalysts had similar activities. (c) 2007 Elsevier B.V. All rights reserved.