The chemical looping dry reforming (CLDR) of methane is a novel technology for F-T ready syngas production and CO₂ utilization  via the circulation of oxygen carrier. Developing an effective OC is crucial for CLDR. Hexaaluminates are a class of excellent high-temperature materials thanks to their peculiar layered structure. The mixed metal oxides or metal doping may improve the redox property of OCs via introducing the strong interaction or synergistic effect.
      In this work, BaFe₃Al₉O₁₉ (BF3) hexaaluminate supported CeO₂ serves as oxygen carrier for CLDR. Combined with a series of characterization, the effect of interaction between CeO₂ and hexaaluminate as a function of calcination temperatures (700, 800, 900 and 1000 ℃) on the CLDR performance was carefully investigated, and then the possible reaction mechanism was proposed (Fig. 1). The results show that fresh CeO₂/BF3 is composed of CeO₂, β-Al₂O₃ and magnetoplumite (MP) hexaaluminate. Increasing the calcination temperature from 700 to 900 ℃ is conducive to enhancing the interaction strength between CeO₂ and hexaaluminate, which favors the diffusion of lattice oxygen to the surface. However, 1000 ◦C calcination leads to the sintering of oxygen carrier, which hinders the migration of lattice oxygen. Among CeO₂/BF3-T (T = 700–1000 ℃), CeO₂/BF3–900 ℃ presents not only a high methane conversion, high syngas yield with ideal H₂/CO ratio (~2), but also excellent CO₂ activation ability and cyclic stability in the periodic CH₄/CO₂ redox cycles, thanks to the highest concentration of Ce³⁺ and Fe²⁺, abundant oxygen vacancies and the formation of CeFe_xAl_1-xO₃.

Chemical looping dry reforming, Methane, CeO2, Hexaaluminate, Oxygen carrier, Interaction