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Leverett J, Daiyan R, Gong L, Iputera K, Tong Z, Qu J, Ma Z, Zhang Q, Cheong S, Cairney J, Liu RS, Lu X, Xia Z, Dai L, Amal R. Designing Undercoordinated Ni-N x and Fe-N x on Holey Graphene for Electrochemical CO 2 Conversion to Syngas. ACS Nano 2021; 15:12006-12018. [PMID: 34192868 DOI: 10.1021/acsnano.1c03293] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this study, we propose a top-down approach for the controlled preparation of undercoordinated Ni-Nx (Ni-hG) and Fe-Nx (Fe-hG) catalysts within a holey graphene framework, for the electrochemical CO2 reduction reaction (CO2RR) to synthesis gas (syngas). Through the heat treatment of commercial-grade nitrogen-doped graphene, we prepared a defective holey graphene, which was then used as a platform to incorporate undercoordinated single atoms via carbon defect restoration, confirmed by a range of characterization techniques. We reveal that these Ni-hG and Fe-hG catalysts can be combined in any proportion to produce a desired syngas ratio (1-10) across a wide potential range (-0.6 to -1.1 V vs RHE), required commercially for the Fischer-Tropsch (F-T) synthesis of liquid fuels and chemicals. These findings are in agreement with our density functional theory calculations, which reveal that CO selectivity increases with a reduction in N coordination with Ni, while unsaturated Fe-Nx sites favor the hydrogen evolution reaction (HER). The potential of these catalysts for scale up is further demonstrated by the unchanged selectivity at elevated temperature and stability in a high-throughput gas diffusion electrolyzer, displaying a high-mass-normalized activity of 275 mA mg-1 at a cell voltage of 2.5 V. Our results provide valuable insights into the implementation of a simple top-down approach for fabricating active undercoordinated single atom catalysts for decarbonized syngas generation.
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Affiliation(s)
- Josh Leverett
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Rahman Daiyan
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Lele Gong
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203, United States
| | - Kevin Iputera
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Zizheng Tong
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Jiangtao Qu
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Zhipeng Ma
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Qingran Zhang
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Soshan Cheong
- Electron Microscope Unit, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Julie Cairney
- Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Ru-Shi Liu
- Department of Chemistry, National Taiwan University, Taipei 106, Taiwan
| | - Xunyu Lu
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Zhenhai Xia
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203, United States
| | - Liming Dai
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Rose Amal
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
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