Mechanism investigation on the synergistic effect between Fe5C2 and Cu in CuFeZn catalysts for the selective hydrogenation of CO2 to ethanol

Siyao Gu, Zhenzhen Yang, Jing Ding, Jun Li, Lei Wang, Hui Wan, Guofeng Guan

Research output: Contribution to journalArticlepeer-review

Abstract

As a promising technology, the selective hydrogenation of CO2 to ethanol using CuFeZn catalysts has attracted significant attention. This study systematically investigates the mechanism of the hydrogenation of CO2 to ethanol over the CuFeZn model catalyst using periodic density functional theory (DFT), with particular focus on the key steps in CO2 hydrogenation. The calculations indicate that the formation of the CO* species is crucial for the production of CH3CH2OH, which requires overcoming an energy barrier of 1.91 eV. The coupling of CO* with CH3* is the rate-determining step, which involves overcoming an energy barrier of 2.77 eV. Further analysis shows that the CuFeZn catalyst's synergistic effect significantly influences CO2 activation and the coupling reaction between CO* and CH3*, thereby enhancing CH3CH2OH formation. The high catalytic performance of the CuFeZn catalyst is attributed to the synergistic interactions between the active Fe5C2 and Cu. Density of States (DOS) and Electronic Localization Function (ELF) analyses show that the elevated Cu d-band center and the high electronic localization of Fe in Fe5C2 enhance the formation of CO* species, thus promoting ethanol synthesis. In summary, by utilizing multiple active components to modulate the generation of CO* species and their activation barriers for coupling with CH3*, the selective production of ethanol can be significantly improved. This study underscores the crucial role of the CuFeZn catalyst for CO2 hydrogenation to ethanol, providing valuable theoretical insights for future catalyst design and optimization.

Original languageEnglish
Article number120375
JournalApplied Catalysis A: General
Volume704
DOIs
StatePublished - 25 Aug 2025

Keywords

  • CO hydrogenation
  • CuFeZn catalyst
  • Density functional theory
  • Ethanol
  • The synergistic effects

Cite this