Highly active La0.35Sr0.35Ba0.3Fe1-xCoxO3 oxygen carriers with the anchored nanoparticles for chemical looping dry reforming of methane

Abstract

Chemical looping dry reforming of methane (CL-DRM) has the potential as a viable technology to achieve carbon neutrality in terms of converting CH4 and CO2 to various value-added products with the minimal separation requirements. However, the design and development of an appropriate oxygen carrier (OC) with the remarkable reactivity and stability make the CL-DRM process challenging. Herein, the Co-substituted La0.35Sr0.35Ba0.3Fe1-xCoxO3 (LSBFC) perovskite oxides with the anchored nanoparticles as the novel OCs were synthesized and investigated for the redox performance in the CL-DRM process. It is found that the best substitution proportion of Co in the anchored perovskite oxides can be set in range of 0.2–0.6. The optimized OCs can greatly improve the reactivity of the chemical looping process based on various characterizations. Among all samples, La0.35Sr0.35Ba0.3Fe0.6Co0.4O3 OC increases the oxygen mobility and shows a higher oxygen diffusion rate to achieve the CH4 conversion of 84.3% and syngas yield of 15.23 mmol⋅g−1 in the CH4 reduction step, respectively. A detailed analysis of the anchored perovskite oxides reveals the substitution of Co can greatly weaken the perovskite lattice to result in the migration of Fe and the formation of Fe nanoparticles, which tremendously promote the activation of CH4 for the further conversion. Furthermore, the excellent OCs also exhibit the high stability in the enhanced reaction performance, the preservation of material structure and the stable regenerability by CO2 during the successive redox cycles. These features demonstrate that the new perovskite materials with anchored nanoparticles can be the promising oxygen carriers for the CL-DRM process.