This study was aimed at developing a suitable oxygen carrier for fluidized bed chemical-looping combustion (CLC) processes. To this end a Co promoted Co-Ni/Al2O3 carrier material was synthesized and evaluated. The reactivity of the solid carrier material was assessed by investigating the energetics and kinetics of metal-support interaction using temperature programmed H-2 desorption technique. The estimated activation of energy of hydrogen desorption for Co-Ni/Al2O3 was found to be less than that of unpromoted Ni/Al2O3 samples. This result suggested that doping the fluidizable oxygen carrier with Co decreases the metal-support interaction and the binding energies between the metals and the H2 molecules, with this playing a significant role to increase the activity of such material. The reactivity and stability of the prepared oxygen carrier particles, under repeated reduction/oxidation cycles, was established in a CREC riser simulator using CH4 and air for the reduction and oxidation cycles, respectively. Over multiple CLC cycles, the Co-Ni/Al2O3 particles displayed excellent reactivity and stability with minimum changes in metal dispersion and crystallite size. Thus, it is concluded that Co might promote the performance of Co-Ni/Al2O3 particles by reducing the metal-support interactions, as assessed using temperature programmed H2 desorption. This reduced interaction has a favorable effect on the oxygen carrier reactivity during the oxidation and reduction reactions. (c) 2007 Elsevier Ltd. All rights reserved.