The Pd(0.15)SiBEA and Co(x)Pd(0.15)SiBEA zeolites (where x = 1.0 and 3.0 wt.% Co) are prepared by a two-step postsynthesis method which allows to control the introduction of palladium and cobalt into zeolite and thus to obtain catalysts with specific bimetallic Pd and Co sites. The effect of Co content on the catalytic activity of Co(x)Pd(0.15)SiBEA zeolites in the selective catalytic reduction (SCR) of NO with methane is investigated. The nature of the active sites is characterized by diffuse reflectance UV-vis, H-2-TPR and XPS. These techniques allow to show that in both Co(1.0)Pd(0.15)SiBEA and Co(3.0)Pd(0.15)SiBEA catalysts the cobalt is present as isolated mononuclear Co(II) species. The catalytic activity of Co(x)Pd(0.15)SiBEA strongly depends on the content of this particular Co(II) species. When Co content increase from 1.0 to 3.0 wt.% the NO conversion in SCR of NO with methane increase from maximum value of 25% to 55%. The conversion of methane is lower than 15% for Co(1.0)Pd(0.15)SiBEA over a wide temperature range (230-460 degrees C) but for Co(3.0)Pd(0.15)SiBEA is much higher at temperature range between 400 and 500 degrees C reaching maximum value of 35% at 500 degrees C. (C) 2011 Elsevier B.V. All rights reserved.