Moderate Surface Segregation Promotes Selective Ethanol Production in CO2 Hydrogenation Reaction over CoCu Catalysts

Sihang Liu; Chengsheng Yang; Shenjun Zha; Dmitry Sharapa; Felix Studt; Zhi-Jian Zhao; Jinlong Gong

doi:10.1002/anie.202109027

Moderate Surface Segregation Promotes Selective Ethanol Production in CO₂ Hydrogenation Reaction over CoCu Catalysts

Angew Chem Int Ed Engl. 2022 Jan 10;61(2):e202109027. doi: 10.1002/anie.202109027. Epub 2021 Nov 30.

Authors

Sihang Liu^{1

2}, Chengsheng Yang¹, Shenjun Zha³, Dmitry Sharapa³, Felix Studt^{3

4}, Zhi-Jian Zhao¹, Jinlong Gong^{1

5}

Affiliations

¹ Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Collaborative Innovation Center of Chemical Science & Engineering, Tianjin University, Weijin Road 92, Tianjin, 300072, China.
² Present address: Catalysis Theory Center, Department of Physics, Technical University of Denmark (DTU), 2800 Kgs., Lyngby, Denmark.
³ Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
⁴ Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, Engesserstr. 18, 76131, Karlsruhe, Germany.
⁵ Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.

PMID: 34676955
DOI: 10.1002/anie.202109027

Abstract

Cobalt-copper (CoCu) catalysts have industrial potential in CO/CO₂ hydrogenation reactions, and CoCu alloy has been elucidated as a major active phase during reactions. However, due to elemental surface segregation and dealloying phenomena, the actual surface morphology of CoCu alloy is still unclear. Combining theory and experiment, the dual effect of surface segregation and varied CO coverage over the CoCu(111) surface on the reactivity in CO₂ hydrogenation reactions is explored. The relationship between C-O bond scission and further hydrogenation of intermediate *CH₂ O was discovered to be a key step to promote ethanol production. The theoretical investigation suggests that moderate Co segregation provides a suitable surface Co ensemble with lateral interactions of co-adsorbed *CO, leading to promoted selectivity to ethanol, in agreement with theory-inspired experiments.

Keywords: CO2 hydrogenation; CoCu alloy; catalyst optimization; ethanol production; surface segregation.

Abstract

Grants and funding