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Chemical looping dry reforming of methane (CLDRM) is performed by exposing a Ni/CeO 2 solid to CH 4 and CO 2 in a cyclic way. The solid acts as an oxygen vector producing syngas (CO + H 2 ) during exposure to CH 4 , and is re-oxidized during exposure to CO 2 . Absence of CO 2 during syngas production allows suppressing reverse water gas shift reaction and reaching high selectivity. Exposure to CO 2 restores the oxygen capacity of the support and removes residual carbon formed at the surface, thus fully regenerating the catalyst. Solids were characterized by TPR, XRD, Raman scattering, and XPS. Results show that part of the Ni is reduced and remain in metallic state during the looping process. On the other hand, Ni 2+ species in strong interaction with Ce cations are observed even after exposure to methane. Both Ni species play important roles on reactants activation and oxygen supply by the solid. Ni loading is a crucial parameter for controlling the reduction behavior of the support and therefore for CLDRM process optimization. [ABSTRACT FROM AUTHOR]

Highlights: [•] Co-precipitation method allows obtaining well-tuned NiXMg2AlOY mixed oxides. [•] The effect of Ni content, activation treatment, and reaction conditions are studied. [•] Total conversion of ethanol at 450°C and CO-free H2 production of 3.0molmolEtOH−1. [•] Good catalytic stability even though solid carbon is formed. [•] Active site involves anionic vacancies, O2− species and cations in close interaction. [ABSTRACT FROM AUTHOR]