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 a-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 pro-vides a strategy to design Fe-based catalysts that can be scaled up for the stable synthesis of HVOs from CO2 hydrogenation.(c) 2023 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

A selective Ba and Na co-modified Fe catalyst enriched with Fe5C2 and Fe3C active sites exhibited high selectivity and stability for the synthesis of high-value olefins from CO2 hydrogenation. The combined effect of Ba and Na additives suppressed catalyst deactivation and stabilized FeCx sites. This study provides a strategy for the design of scalable Fe-based catalysts for the stable synthesis of high-value olefins.