Reversible Phase Transformations in Novel Ce?Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO ₂

Thermochemical splitting of CO2 and H2O via two-step metal oxide redox cycles offers a promising approach to produce solar fuels. Perovskite-type oxides with the general formula ABO3 have recently gained attention as an attractive material alternative state-of-the-art ceria, due their high structural thermodynamic tunability. A novel Ce-substituted lanthanum strontium manganite perovskite-oxide composite, La3+0.48Sr2+0.52(Ce4+0.06Mn3+0.79)O2.55 (LSC25M75) is introduced, aiming bridge gap between ceria perovskite oxide-based materials by overcoming individual constraints. cyclability LSC25M75 evaluated thermogravimetric analyzer infrared furnace reactor over 100 consecutive demonstrates twofold higher conversion extent CO than one best Mn-based oxides, La0.60Sr0.40MnO3. Based on complementary in situ temperature neutron, synchrotron X-ray, electron diffraction experiments, unprecedented mechanistic insight obtained into thermochemical materials. reaction mechanism presented, involving reversible induced phase transitions from n = 1 Ruddlesden–Popper (Sr1.10La0.64Ce0.26)MnO3.88 (I4/mmm, K2NiF4-type) at reduction (1350 °C) 2 (Sr2.60La0.22Ce0.18)Mn2O6.6 Sr3Ti2O7-type) re-oxidation (1000 after step.