La-induced stabilization of Fe-Ni active phases in NiFe2O4 via in situ LaFeO3 formation for efficient CO2 hydrogenation to CO

La promotes surface electron transfer in NiFe 2 O 4 to form La-Fe-O precursors. • In-situ LaFeO 3 perovskite scaffold physically confines and anchors active grains. • 20% La doping optimizes the synergy between active site exposure and stability. • Lattice reconstruction enables a high CO 2 conversion of 73% at 700 °C. • Stable CO 2 conversion above 97% over 30 h continuous operation. Catalytic hydrogenation of CO 2 to CO via the reverse water-gas shift (RWGS) reaction provides an attractive route for renewable hydrogen utilization and carbon recycling. NiFe 2 O 4 spinels are promising RWGS catalysts owing to abundant oxygen vacancies and excellent CO 2 activation capability. However, the reconstruction-induced aggregation of Fe-Ni active phases under reaction conditions severely limits durability. Herein, La modification regulates phase reconstruction, surface basicity, and oxygen environments. La-induced electron transfer promotes Ni reduction, modifies Fe-O coordination, and enriches defect-related and adsorbed oxygen species, enhancing CO 2 activation. Meanwhile, LaFeO 3 anchors Fe-Ni nanocrystals and suppresses FeO accumulation and sintering. Consequently, 20La 2 O 3 -NiFe 2 O 4 achieves 73.0% CO 2 conversion at 700 °C, and 2.33 times that of pristine NiFe 2 O 4 , while retaining approximately 97% of its initial conversion after 30 h. This work provides an effective strategy for active-phase stabilization, advancing the development of durable catalysts for efficient CO 2 hydrogenation. Download: Download high-res image (317KB) Download: Download full-size image