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Electrochemical Generation of Catalytically Active Edge Sites in C₂N‐Type Carbon Materials for Artificial Nitrogen Fixation

Zhang, Wuyong ; Zhan, Shaoqi ; Qin, Qing ; Heil, Tobias ; Liu, Xiyu ; Hwang, Jinyeon ; Ferber, Thimo H. ; Hofmann, Jan P. ; Oschatz, Martin (2022)
Electrochemical Generation of Catalytically Active Edge Sites in C₂N‐Type Carbon Materials for Artificial Nitrogen Fixation.
In: Small : nano micro, 18 (42)
doi: 10.1002/smll.202204116
Artikel, Bibliographie

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Kurzbeschreibung (Abstract)

The electrochemical nitrogen reduction reaction (NRR) to ammonia (NH₃) is a potentially carbon‐neutral and decentralized supplement to the established Haber–Bosch process. Catalytic activation of the highly stable dinitrogen molecules remains a great challenge. Especially metal‐free nitrogen‐doped carbon catalysts do not often reach the desired selectivity and ammonia production rates due to their low concentration of NRR active sites and possible instability of heteroatoms under electrochemical potential, which can even contribute to false positive results. In this context, the electrochemical activation of nitrogen‐doped carbon electrocatalysts is an attractive, but not yet established method to create NRR catalytic sites. Herein, a metal‐free C₂N material (HAT‐700) is electrochemically etched prior to application in NRR to form active edge‐sites originating from the removal of terminal nitrile groups. Resulting activated metal‐free HAT‐700‐A shows remarkable catalytic activity in electrochemical nitrogen fixation with a maximum Faradaic efficiency of 11.4% and NH₃ yield of 5.86 µg mg⁻¹cat h⁻¹. Experimental results and theoretical calculations are combined, and it is proposed that carbon radicals formed during activation together with adjacent pyridinic nitrogen atoms play a crucial role in nitrogen adsorption and activation. The results demonstrate the possibility to create catalytically active sites on purpose by etching labile functional groups prior to NRR.

Typ des Eintrags: Artikel
Erschienen: 2022
Autor(en): Zhang, Wuyong ; Zhan, Shaoqi ; Qin, Qing ; Heil, Tobias ; Liu, Xiyu ; Hwang, Jinyeon ; Ferber, Thimo H. ; Hofmann, Jan P. ; Oschatz, Martin
Art des Eintrags: Bibliographie
Titel: Electrochemical Generation of Catalytically Active Edge Sites in C₂N‐Type Carbon Materials for Artificial Nitrogen Fixation
Sprache: Englisch
Publikationsjahr: 2022
Ort: Darmstadt
Verlag: Wiley-VCH
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Small : nano micro
Jahrgang/Volume einer Zeitschrift: 18
(Heft-)Nummer: 42
Kollation: 9 Seiten
DOI: 10.1002/smll.202204116
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Kurzbeschreibung (Abstract):

The electrochemical nitrogen reduction reaction (NRR) to ammonia (NH₃) is a potentially carbon‐neutral and decentralized supplement to the established Haber–Bosch process. Catalytic activation of the highly stable dinitrogen molecules remains a great challenge. Especially metal‐free nitrogen‐doped carbon catalysts do not often reach the desired selectivity and ammonia production rates due to their low concentration of NRR active sites and possible instability of heteroatoms under electrochemical potential, which can even contribute to false positive results. In this context, the electrochemical activation of nitrogen‐doped carbon electrocatalysts is an attractive, but not yet established method to create NRR catalytic sites. Herein, a metal‐free C₂N material (HAT‐700) is electrochemically etched prior to application in NRR to form active edge‐sites originating from the removal of terminal nitrile groups. Resulting activated metal‐free HAT‐700‐A shows remarkable catalytic activity in electrochemical nitrogen fixation with a maximum Faradaic efficiency of 11.4% and NH₃ yield of 5.86 µg mg⁻¹cat h⁻¹. Experimental results and theoretical calculations are combined, and it is proposed that carbon radicals formed during activation together with adjacent pyridinic nitrogen atoms play a crucial role in nitrogen adsorption and activation. The results demonstrate the possibility to create catalytically active sites on purpose by etching labile functional groups prior to NRR.

Freie Schlagworte: activation, electrocatalysis, nitrogen fixation, nitrogen‐doped carbon
Sachgruppe der Dewey Dezimalklassifikatin (DDC): 500 Naturwissenschaften und Mathematik > 540 Chemie
600 Technik, Medizin, angewandte Wissenschaften > 660 Technische Chemie
Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Oberflächenforschung
Hinterlegungsdatum: 02 Aug 2024 12:47
Letzte Änderung: 02 Aug 2024 12:47
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