Elucidating the Copper–Hägg Iron Carbide Synergistic Interactions for Selective CO Hydrogenation to Higher Alcohols

CO hydrogenation to higher alcohols (C2+OH) provides a promising route to convert coal, natural gas, shale gas, and biomass feedstocks into value-added chemicals and transportation fuels. However, the development of nonprecious metal catalysts with satisfactory activity and well-defined selectivity...

Full description

Saved in:
Bibliographic Details
Published in:ACS catalysis 2017-08, Vol.7 (8), p.5500-5512
Main Authors: Lu, Yongwu, Zhang, Riguang, Cao, Baobao, Ge, Binghui, Tao, Franklin Feng, Shan, Junjun, Nguyen, Luan, Bao, Zhenghong, Wu, Tianpin, Pote, Jonathan W., Wang, Baojun, Yu, Fei
Format: Article
Language:English
Subjects:
CO hydrogenation
copper
Hagg iron carbide
higher alcohols
reaction mechanism
synergistic effect
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:CO hydrogenation to higher alcohols (C2+OH) provides a promising route to convert coal, natural gas, shale gas, and biomass feedstocks into value-added chemicals and transportation fuels. However, the development of nonprecious metal catalysts with satisfactory activity and well-defined selectivity toward C2+OH remains challenging and impedes the commercialization of this process. Here, we show that the synergistic geometric and electronic interactions dictate the activity of Cu-0-chi-Fe5C2 binary catalysts for selective CO hydrogenation to C2+OH, outperforming silica-supported precious Rh-based catalysts, by using a combination of experimental evidence from bulk, surface-sensitive, and imaging techniques collected on real and high-performance Cu-Fe binary catalytic systems coupled with density functional theory calculations. The closer is the d-band center to the Fermi level of Cu-0-chi-Fe5C2(510) surface than those of chi-Fe5C2(510) and Rh(111) surface, and the electron-rich interface of Cu-0-chi-Fe5C2(510) due to the delocalized electron transfer from Cu-0 atoms, facilitates CO activation and CO insertion into alkyl species to C-2-oxygenates at the interface of Cu-0-chi-Fe5C2(510) and thus enhances C2H5OH selectivity. Starting from the CHCO intermediate, the proposed reaction pathway for CO hydrogenation to C2H5OH on Cu-0-chi-Fe5C2(510) is CHCO + (H) -> CH2CO + (H) -> CH3CO + (H) -> CH3CHO + (H) -> CH3CH2O + (H) -> C2H5OH. This study may guide the rational design of high-performance binary catalysts made from earth-abundant metals with synergistic interactions for tuning selectivity.
ISSN:2155-5435
2155-5435
DOI:10.1021/acscatal.7b01469