Tuning the surface carbonaceous species in syngas-to-olefin reaction by metal-support interaction: A Fe-Mn-Al ternary system study

Fabrication of active iron carbides is essential for CO dissociation and carbon chain growth, but also faces a challenge of controlling the rate of carbon deposition to avoid rapid deactivation. In this context, we synthesized a Mn-Al supported Fe catalysts exhibiting low carbon deposits by carefully controlling the metal-support interaction. Al may enhance the hydrothermal stability of FeCx, and facilitate the hydrogenation and desorption of hydrocarbons. These effects reduce the amount of carbon precursors on the surface so that the carbon coupling ability not only in carbon deposits but also in hydrocarbons can be weakened, and the Fe/Mn2Al1 exhibits the highest conversion (12.5 %) of CO and C2–4= yield (189. 9 g·kg−1cat·h−1). [Display omitted] •Mn/Al ratio modulates Fe-Mn interaction, carbon species, and chain growth ability for optimal STO performance.•Al enhances hydrothermal stability of FeCx, reduces carbon precursor amount, and weakens carbon coupling ability.•Novel Mn-Al supported Fe catalysts offer low carbon deposits by controlling metal-support interaction.