Exsolution-Driven Layered Perovskites for Stable Thermal Carbon Capture and Utilization of Waste Streams.

Abstract

Integrated carbon capture and utilization (ICCU) presents a sustainable route for simultaneous valorization of CO₂ and solid waste, yet maintaining cyclic stability under high-temperature conditions remains challenging. Here, we construct dual-functional materials based on Ni-substituted layered perovskite Sr₂TiO₄, engineering to enhance Ni-substrate interactions, thereby stabilizing ICCU reactions via in situ exsolution. Systematic experiments and characterizations reveal that gradual Ni exsolution from the Sr₂TiO₄/SrTiO₃ matrix during cyclic reactions yields well-dispersed, surface-anchored Ni nanoparticles. This dynamic process drives progressively increasing, then stabilized, CO₂ uptakes and syngas productions across cycles, contrasting sharply with the deactivation of predeposited Ni system. Moreover, electronic structure analysis reveals that CO emissions from exsolved Ni-driven CO₂ splitting are both more kinetically unfavorable than Sr₂TiO₄ carbonation and effectively suppressed by O₂ in the flue gas. These findings demonstrate a robust strategy for efficient co-utilization of CO₂ and solid waste under demanding thermochemical conditions.