Remarkable solar thermochemical CO2 splitting performances based on Ce- and Al-doped SrMnO3 perovskites

Solar thermochemical CO2 splitting has emerged as a promising strategy for solar fuel production to alleviate climate change challenges and reduce the energy crisis. However, traditional redox materials still suffer from low CO production, poor cycle stability, high operating temperature, and large temperature swing, leading to low solar-to-fuel efficiency. Herein, Ce- and Al-doped SrMnO3 perovskites are proposed for high-performance solar thermochemical CO2 splitting within moderate temperature swing (1350/1100 °C). Sr0.6Ce0.4Mn0.8Al0.2O3 demonstrates a remarkable CO yield of 799.34 μmol g−1, which is ∼6.67 times as high as that of benchmark CeO2. Fast CO2 splitting kinetics of SCMA20 is demonstrated by the CO peak production rate enhanced by 142% compared with undoped SrMnO3. The proposed Sr0.6Ce0.4Mn0.8Al0.2O3 also exhibits excellent stability with no obvious deactivation or degradation over multiple cycles. The ultrahigh CO yield can be attributed to lower oxygen vacancy formation (3.65 eV) and migration energy (2.14 eV) as confirmed by DFT calculations, and the transformation of the first-order reaction (F1) to the second-order reaction (F2) compared to SrMnO3. This work provides a new path for high-performance solar thermochemical CO2 splitting with high CO production, fast reaction kinetics, good cycling stability, moderate temperature swing, and high solar absorptance.