Stabilized ε-FeC catalyst with Mn tuning to suppress C1 byproduct selectivity for high-temperature olefin synthesis.

Accurately controlling the product selectivity in syngas conversion, especially increasing the olefin selectivity while minimizing C1 byproducts, remains a significant challenge. Epsilon FeC is deemed a promising candidate catalyst due to its inherently low CO selectivity, but its use is hindered by its poor high-temperature stability. Herein, we report the successful synthesis of highly stable ε-FeC through a N-induced strategy utilizing pyrolysis of Prussian blue analogs (PBAs). This catalyst, with precisely controlled Mn promoter, not only achieved an olefin selectivity of up to 70.2% but also minimized the selectivity of C1 byproducts to 19.0%, including 11.9% CO and 7.1% CH. The superior performance of our ε-FeC-xMn catalysts, particularly in minimizing CO formation, is largely attributed to the interface of dispersed MnO cluster and ε-FeC, which crucially limits CO to CO conversion. Here, we enhance the carbon efficiency and economic viability of the olefin production process while maintaining high catalytic activity.