Cobalt-zeolite-Y (Co-Y), was investigated utilizing synchrotron X-ray microtomography, EXAFS, and XANES measurements. X-ray microtomography showed an inhomogeneous distribution of cobalt ions with cobalt-rich domains of 50 mum diameter. XANES measurements fixed the oxidation state of the cobalt ion to be +2.35. EXAFS measurements revealed the cobalt-oxygen bond distance to be 1.7 Angstrom. The cobalt-cobalt bond distance was fixed at 2.8 Angstrom. X-ray microtomography showed cobalt-rich regions made up 16.81% of the cobalt-zeolite complex. This information was used to characterize the transition metal-zeolite complex.