Intensified solar thermochemical CO2 splitting over iron-based redox materials via perovskite-mediated dealloying-exsolution cycles

Solar thermochemical CO2-splitting (STCS) is a promising solution for solar energy harvesting and storage. However, practical fuel production by utilizing earth-abundant iron/iron oxides remains great challenge because of the formation passivation layers, resulting in slow reaction kinetics limited CO2 conversion. Here, we report novel material consisting an iron-nickel alloy embedded perovskite substrate intensified CO via two-step STCS process. The achieved unprecedented rate 381 mL g−1 min−1 with 99% conversion at 850 °C, outperforming state-of-the-art materials. In situ structural analyses density functional theory calculations show that alloy/substrate interface main active site splitting. Preferential oxidation FeNi (as opposed to forming FeOx shell encapsulating bare metallic iron) rapid stabilization iron oxide species robust matrix significantly promoted CO. Facile regeneration alloy/perovskite interfaces was realized isothermal methane reduction simultaneous syngas (H2/CO = 2, yield > 96%). Overall, perovskite-mediated dealloying-exsolution redox system facilitates highly efficient production, theoretical solar-to-fuel efficiency up 58%, absence any heat integration.