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 CO 2 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 Sr 2 TiO 4 , 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 Sr 2 TiO 4 /SrTiO 3 matrix during cyclic reactions yields well‐dispersed, surface‐anchored Ni nanoparticles. This dynamic process drives progressively increasing, then stabilized, CO 2 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 CO 2 splitting are both more kinetically unfavorable than Sr 2 TiO 4 carbonation and effectively suppressed by O 2 in the flue gas. These findings demonstrate a robust strategy for efficient co‐utilization of CO 2 and solid waste under demanding thermochemical conditions.