Performance of Iron-Based Perovskite-type Oxides for Chemical Looping Dry Reforming of Methane

Partial oxidation of methane has emerged as a promising approach for the effective utilization of methane. When combined with the thermochemical CO2 reduction through the “chemical looping” concept, it can realize the coproduction of syngas and high-purity carbon monoxide. In this study, we proposed a chemical looping dry reforming of methane (CL-DRM) process by using iron-based perovskite-type oxides as oxygen carriers (OCs). This process has the potential to efficiently utilize low-grade solar heat and convert it into high-grade chemical energy. To identify efficient perovskite-type OCs, we synthesized and characterized LaFeO3, SrFeO3, La0.5Sr0.5FeO3, SrFe0.5Ni0.5O3, and LaFe0.5Ni0.5O3. The candidates were evaluated via H2/CH4 temperature-programmed reduction and isothermal chemical looping redox cycles within the temperature range of 750–950 °C, revealing their potential for integration into the CL-DRM system. A series of characterization tests were tested to unveil the reaction mechanism for different iron-based perovskites. The results demonstrate that the introduction of nickel substitution enhances the activity of the iron-based perovskites, and lanthanum proves to be the more suitable A-site element for these materials. Among the candidates, LaFeO3 shows the highest performance at 950 °C; LaFe0.5Ni0.5O3 exhibits the best reactivity, CO selectivity, and carbon resistance at 750 and 850 °C. Our study is expected to facilitate the development of efficient and clean methane conversion, while simultaneously advancing solar thermochemical fuel production and CO2 utilization.