Tailoring redox behavior of A-site defected LaxFe1-yNiyO3-δ perovskite oxygen carrier for chemical looping dry reforming of methane

• Selective partial oxidation of methane into syngas. • Modification of perovskite redox properties via multi-pathways. • Structure-oxygen storage relationship of the perovskite in chemical looping. Chemical looping dry reforming of methane (CL-DRM) is a promising process for syngas production. However, its application is limited by the trade-off between activity and selectivity in redox reactions. Herein, we designed efficient La x Fe 1-y Ni y O 3-δ (0.9 ≤ x ≤ 1.0, 0.05 ≤ y ≤ 0.4) perovskite-type oxygen carriers (OCs) for CL-DRM via A-site defect engineering and B-site doping. Compared to stoichiometric LaFeO 3 , the optimized OCs exhibited enhanced oxygen mobility, which resulted in 20.7 % higher methane conversion, 33.8 % greater syngas yield, and retention of over 90 % carbon monoxide selectivity. Experimental results reveal that absence of La cation improved the oxygen vacancy concentration and oxygen mobility which promoted the partial oxidation of methane. This defect engineering scheme effectively alleviates sintering and inhibits carbon deposition (Raman I D /I G = 0.7). Consequently, the OCs exhibit structural stability and regeneration ability throughout 50 redox cycles. This study provides a simple and effective strategy for tuning the redox properties of perovskite oxides for thermochemical or redox-related reactions.