High-entropy perovskite oxides for direct solar-driven thermochemical CO2 splitting

Abstract

The global energy crisis and climate change have fueled interest in solar-driven thermochemical CO2 splitting as a potential solution. However, conventional materials like CeO2 encounter limitations attributable to their low solar absorptivity and CO yield (even at high reduction temperatures), exerting a detrimental influence on both solar energy utilization and process efficiency. This study proposes high-entropy A-site doped perovskites as a potential solution for efficient solar thermochemical CO2 splitting. The increased configurational entropy enhances the solar thermal CO2 splitting cycles by decreasing oxygen vacancy formation energy and lattice oxygen migration energy barrier. This is supported by experimental results, where Sm0.25Sr0.25Ca0.25La0.25MnO3 achieved a maximum CO yield of 764.76 μmol g−1 with low temperature difference between the reduction and oxidation steps, marking an important progress in solar thermal CO2 splitting cycles. The study demonstrates the potential of high-entropy perovskites for direct solar energy harvesting with high spectrum absorption coefficients and sustainable CO2 utilization.