Boosting CO₂ hydrogenation to high-value olefins with highly stable performance over Ba and Na co-modified Fe catalyst

CO₂ hydrogenation has been considered to be a highly promising route for the production of high-value olefins (HVOs) while also mitigating CO₂ emissions. However, it is challenging to achieve high selectivity and maintain stable performance for HVOs (ethylene, propylene, and linear α-olefins) over a prolonged reaction time due to the difficulty in precise control of carbon coupling and rapid catalyst deactivation. Herein, we present a selective Ba and Na co-modified Fe catalyst enriched with Fe₅C₂ and Fe₃C active sites that can boost HVO synthesis with up to 66.1% selectivity at an average CO₂ conversion of 38% for over 500 h. Compared to traditional NaFe catalyst, the combined effect of Ba and Na additives in the NaBaFe-0.5 catalyst suppressed excess oxidation of FeC_x sites by H₂O. The absence of Fe₃O₄ phase in the spent NaBaFe-0.5 catalyst reflects the stabilization effect of the co-modifiers on the FeC_x sites. This study provides a strategy to design Fe-based catalysts that can be scaled up for the stable synthesis of HVOs from CO₂ hydrogenation.