High-yield production of liquid fuels in CO hydrogenation on a zeolite-free Fe-based catalyst

• Published in: Chemical science (Cambridge) Vol. 14; no. 1; pp. 171 - 178
• Main Authors: Guo, Lisheng, Gao, Xinhua, Gao, Weizhe, Wu, Hao, Wang, Xianbiao, Sun, Song, Wei, Yuxue, Kugue, Yasuharu, Guo, Xiaoyu, Sun, Jian, Tsubaki, Noritatsu
• Format: Journal Article
• Published: 21.12.2022
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/d2sc05047a

Catalytic conversion of CO 2 to long-chain hydrocarbons with high activity and selectivity is appealing but hugely challenging. For conventional bifunctional catalysts with zeolite, poor coordination among catalytic activity, CO selectivity and target product selectivity often limit the long-chain hydrocarbon yield. Herein, we constructed a singly cobalt-modified iron-based catalyst achieving 57.8% C 5+ selectivity at a CO 2 conversion of 50.2%. The C 5+ yield reaches 26.7%, which is a record-breaking value. Co promotes the reduction and strengthens the interaction between raw CO 2 molecules and iron species. In addition to the carbide mechanism path, the existence of Co 3 Fe 7 sites can also provide sufficient O-containing intermediate species (CO*, HCOO*, CO 3 2 *, and ) for subsequent chain propagation reaction via the oxygenate mechanism path. Reinforced cascade reactions between the reverse water gas shift (RWGS) reaction and chain propagation are achieved. The improved catalytic performance indicates that the KZFe-5.0Co catalyst could be an ideal candidate for industrial CO 2 hydrogenation catalysts in the future. CO 2 /H 2 mixtures can be directly converted into long-chain hydrocarbons with a yield of 26.7% over a bimetallic FeCo catalyst via strengthening the reinforced chain growth reaction.