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 FeCx 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 FeCx 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.