Study on the optimization of preparation parameters for the Ba ₅ CaFe ₄ O ₁₂ oxygen carrier

Oxygen‐enriched combustion is an effective strategy for reducing carbon dioxide emissions; however, its application is limited by the high cost of oxygen production. Chemical‐looping air separation (CLAS) offers a promising alternative due to its low energy consumption, cost efficiency, and operational simplicity, with the oxygen carrier serving as a key component. This study investigates the optimization of preparation parameters for the Ba 5 CaFe 4 O 12 oxygen carrier, which operates effectively at relatively low reaction temperatures. The effects of calcination temperature (1050–1200°C), duration (6–12 h), and atmosphere (nitrogen and air) on the oxygen absorption and release kinetics, phase composition, surface morphology, and pore structure were systematically analyzed using the solid‐state reaction method. Results indicate that all samples exhibit the Ba 5 CaFe 4 O 12 phase when the calcination time exceeds 6 h. Increasing calcination temperature leads to particle sintering and agglomeration, reducing specific surface area and enlarging pore size. When calcination time surpasses 10 h, severe sintering occurs, adversely affecting oxygen exchange performance. Moreover, calcination under air atmosphere reduces surface area and pore volume, diminishing oxygen absorption and release capacity. Under the experimental conditions, the optimal preparation parameters were determined as 1050°C for 10 h under a nitrogen atmosphere, yielding a well‐developed Ba 5 CaFe 4 O 12 structure with excellent oxygen exchange behavior. This work provides practical guidance for designing efficient oxygen carriers in chemical‐looping systems for low‐cost and energy‐saving oxygen production.