The objective of this study was to use Mg to improve the performance in chemical looping combustion. Oxygen carrier particles were synthesized in which Mg was doped into the M-sites with Fe, Co, Ni, and Cu to produce FeaMgbOx, CoaMgbOx, NiaMgbOx, and CuaMgbOx, respectively, with M/Mg ratios ranging from 1.5 to 3.0. The structure and properties of the prepared samples were characterized using XRD, SEM, CH4-/CO-TPD, XPS, and TGA. The XRD results explore that the Fe(2)Mg10x sample has a pure cubic structure of Fe2MgO4, whereas the Co(2)Mg10x and Ni(2)Mg10x samples exist as a solid solution. Nevertheless, the mixed compound formation of orthorhombic structure of Cu2MgO3 and cubic structure of MgO has been observed in Cu(2)Mg10x. The CH4 absorption is the highest on the Cu(2)Mg10x sample according to the CH4-TPD results. The CO-TPD and H-2-TPR results showed that the adsorption of the Cu and Mg complex metal oxide is higher than that of the pure metal oxide. The oxygen carrier capacity of the samples was studied by isothermal H-2 (FR)/air (AR) and CH4 (FR)/air (AR) redox cycle experiments at 850 degrees C using TGA. The promising results obtained from chemical looping combustion indicate that the CuaMgbOx samples are potentially useful for CLC in H-2 and CH4 atmospheres. (C) 2017 Elsevier B.V. All rights reserved.