High-Throughput Exploration of Perovskite Oxides for Chemical Looping Air Separation

Abstract The structural and operational flexibility of perovskite oxides makes them uniquely suited for chemical looping air separation. While prior work has largely focused on SrFeO3–δ type perovskites, the vast unexplored compositional space warrants a systematic investigation. Here, a rational approach to designing perovskite oxides with phase stability and oxygen storage capacity under thermodynamically favorable conditions is presented. Using a DFT (density functional theory)-based high-throughput model, 23,716 AxA′1–xByB′1–yO3–δ compositions are explored, and 193 candidates are predicted to be capable of spontaneous oxygen exchange under isothermal pressure swing conditions (0.2–0.01 atm O2) at 400 °C and 600 °C. Convex hull analysis with an Ehull threshold of 75 meV/atom further eliminates a substantial fraction of unstable compositions, notably reducing the experimental burden. Experimental validation confirms the phase stability and oxygen exchange ability of 8 sorbent compositions, including several previously unreported materials that would be difficult to identify through conventional empirical screening. The model also identifies Ca0.25Sr0.75Fe0.875Ni0.125O3–δ, which has exceptional oxygen capacity due to its ability to undergo phase transition at 400 °C under pressure swing. These findings highlight the effectiveness of our combinatorial approach and, together with a few potential improvements based on this study, can accelerate future material discoveries.