Synergistic effect of K and Zn on Fe-based catalysts for efficient CO2 hydrogenation

Jia-Min Lyu; Shen Yu; Zhan Liu; He-You Du; Ming-Hui Sun; Chun-Mu Guo; Yi-Long Wang; Yu Li; Li-Hua Chen; Bao-Lian Su

doi:10.1039/d3dt03913g

Synergistic effect of K and Zn on Fe-based catalysts for efficient CO₂ hydrogenation

Dalton Trans. 2024 Feb 6;53(6):2526-2533. doi: 10.1039/d3dt03913g.

Authors

Jia-Min Lyu¹, Shen Yu¹, Zhan Liu^{1

2

3}, He-You Du^{1

2}, Ming-Hui Sun¹, Chun-Mu Guo¹, Yi-Long Wang⁴, Yu Li¹, Li-Hua Chen¹, Bao-Lian Su^{1

5}

Affiliations

¹ Laboratory of Living Materials at the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, 122 Luoshi Road, Wuhan, 430070, Hubei, China. ironman@whut.edu.cn.
² International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, 430070, Hubei, China.
³ Nanostructure Research Center, Wuhan University of Technology, Wuhan, 430070, Hubei, China.
⁴ School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan, 430070, Hubei, China.
⁵ Laboratory of Inorganic Materials Chemistry, University of Namur, 61 rue de Bruxelles, B-5000 Namur, Belgium.

PMID: 38226637
DOI: 10.1039/d3dt03913g

Abstract

Excessive emission of CO₂ into the atmosphere has severely impacted the global ecological environment. Converting CO₂ into valuable chemicals and fuels is of great significance for sustainable development. However, low activity and undesirable selectivity often result from the inherent inertness of CO₂. Herein, K- or/and Zn-modified Fe-based catalysts were prepared by an incipient-wetness impregnation method for CO₂ hydrogenation via a cascade reaction. The results indicate that K species exist as K₂O while Zn species exist as ZnFe₂O₄. In the CO₂ hydrogenation pathway, K₂O facilitates the adsorption of CO₂ and restrains the adsorption of H₂, accelerating the transformation of CO₂ into C₂-C₄ olefins rather than paraffins while Zn species promote the dispersion of Fe species, leading to improved activity. Synergistically, a K- and Zn-modified Fe-based catalyst (2Zn-10K-Fe/Al) shows excellent catalytic CO₂ hydrogenation activity, achieving a CO₂ conversion of 77% which is 1.8 times that (42%) of the unmodified Fe-based catalyst (Fe/Al). Our catalyst also shows a significantly promoted selectivity to C₂-C₄ olefins of 17% in comparison with the Fe/Al catalyst (0%). It is envisioned that such a binary effect of elements might contribute to the low-cost and industrial production of Fe-based catalysts for selective CO₂ conversion.