In situ synthesis of highly dispersed Fe/C catalysts with pomelo peel as carbon source in CO2 hydrogenation to light olefins

• A highly dispersed Fe/C catalyst was prepared using pomelo peel as carbon source. • Fe/C catalyst achieved an excellent STY in CO 2 hydrogenation to light olefins. • Metal-support interaction can be regulated by pyrolysis temperature. • Excellent performance is due to the rich functional groups, Fe 3 O 4 and Fe 5 C 2 . Although considerable progress has been made in the hydrogenation of CO 2 to light olefins through the modified Fischer-Tropsch synthesis route (CO 2 -FTS), the design of catalysts with high selectivity and stability is still a challenge. Herein, a simple, highly dispersed and scalable Fe/C-400 catalyst was prepared by in-situ pyrolysis using pomelo peel (PP) as carbon source, and was first used in CO 2 hydrogenation to light olefins. This catalyst exhibited a high space time yield of light olefins (48.3 μmol CO2 ·g Fe −1 ·s −1 ), and the light olefins selectivity and O/P were 63.0% and 9.0, respectively. More surprisingly, no obvious deactivation was observed within 200 h. A series of characterization techniques such as TEM, TG-MS, FTIR, XPS, H 2 -TPR and 57 Fe Mössbauer spectrum showed that the naturally abundant oxygen-containing functional groups in PP support could impart metal-support interactions that enhance the dispersion of iron species. The modulation of the catalyst phase composition was achieved by simply varying the residual amount of oxygen-containing functional groups to impart different metal-support interactions. The catalysts prepared at lower pyrolysis temperatures retained more oxygen-containing functional groups and therefore had stronger metal-support interactions, which facilitated the formation of more active phases. Overall, this newly developed catalyst realized the high activity and high stability production of CO 2 hydrogenation to light olefins, providing a cost-effective and sustainable way for its industrial application.