A CoSiBEA zeolite was obtained by a postsynthesis method which consisted of a treatment of tetraethylammonium BEA zeolite with nitric acid in the first step and introduction of Co ions into the vacant T atom sites of the SiBEA zeolite by reaction of aqueous Co(NO3)2 solution with silanol groups. The introduction of Co into SiBEA zeolite as a isolated mononuclear Co(II) was evidenced by XRD, FTIR, diffuse reflectance UV–vis, and XPS. Brønsted and Lewis acidity of HAlBEA, SiBEA, and CoSiBEA zeolites were investigated by FTIR spectroscopy using pyridine as the probe molecule. Reducibility of cobalt in CoSiBEA zeolites was investigated by temperature-programmed reduction of H2. Dispersion of metallic cobalt nanoparticles was determined by transmission electron microscopy.