Improvement of oxygen transfer capacity by migration of oxygen defects formed in CuxMg1−xFeyTi2−yOz particles

[Display omitted] •Cu0.5Mg0.5FeTiO5 particle was composed of a co-mixture of CuMgTiO4 inverse spinel and Fe2TiO5 Karroite.•CH4 and CO gases selectively adsorbed on the surfaces of Cu and Fe ions, respectively.•Oxygen transfer capacity of Cu0.5Mg0.5FeTiO5 in CH4–CO2/air redox system exhibited 6.37%.•Improvement of oxygen transfer capacity was caused by oxygen migrations through oxygen defects in crystal structure. This study focuses on the improvement of oxygen transfer capacity of CuxMg1−xFeyTi2−yOz particle which simultaneously inserted with Cu2+ and Fe3+ ions into the Mg1.0Ti2.0O5.0 Karroite. The prepared Cu0.5Mg0.5Fe1.0Ti1.0O4.5 particle was composed of a co-mixture of a cubic Mg2TiO4 inverse spinel and an orthorhombic Fe2TiO5 Karroite. The CH4 and CO gases were selectively adsorbed on the surfaces of Cu and Fe ions, respectively, suggested that during the CLC, the Cu2+ and Fe3+ components had more effect to the methane combustion reaction and carbon monoxide oxidation. The oxygen transfer capacities of the Cu0.5Mg0.5Fe1.0Ti1.0O4.5 in the H2/air and CH4–CO2/air redox systems exhibited 9.59 % and 6.37 %, respectively. The difference of 3.22% in two systems corresponded to the affection of Fe2+. This work eventually revealed that when the Cu2+ and Fe3+ ions were simultaneously inserted for the Mg1.0Ti2.0O5.0 Karroite, their coexistence can improve the oxygen carrier capacity by a rapid oxygen migration through oxygen vacancies formed in lattice.