Unveiling the Protonation Kinetics-Dependent Selectivity in Nitrogen Electroreduction: Achieving 75.05 % Selectivity

Yang Liu; Lingling Wang; Lin Chen; Hongdan Wang; Amol R Jadhav; Taehun Yang; Yixuan Wang; Jinqiang Zhang; Ashwani Kumar; Jinsun Lee; Viet Q Bui; Min Gyu Kim; Hyoyoung Lee

doi:10.1002/anie.202209555

Unveiling the Protonation Kinetics-Dependent Selectivity in Nitrogen Electroreduction: Achieving 75.05 % Selectivity

Angew Chem Int Ed Engl. 2022 Dec 12;61(50):e202209555. doi: 10.1002/anie.202209555. Epub 2022 Nov 17.

Authors

Yang Liu^{1

2}, Lingling Wang^{1

2}, Lin Chen³, Hongdan Wang^{1

2}, Amol R Jadhav¹, Taehun Yang^{1

2}, Yixuan Wang^{1

2}, Jinqiang Zhang⁴, Ashwani Kumar^{1

2}, Jinsun Lee^{1

2}, Viet Q Bui⁵, Min Gyu Kim⁶, Hyoyoung Lee^{1

2

7

8}

Affiliations

¹ Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
² Department of Chemistry, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
³ State Key Laboratory of Fine Chemicals, Liaoning Key Lab for Energy Materials and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, China.
⁴ School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA 5005, Australia.
⁵ Advanced Institute of Science and Technology, The University of Danang, 41 Le Duan, Danang, Vietnam.
⁶ Beamline Research Division, Pohang Accelerator Laboratory (PAL), Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.
⁷ Creative Research Institute, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
⁸ Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.

PMID: 36289044
DOI: 10.1002/anie.202209555

Abstract

While higher selectivity of nitrogen reduction reaction (NRR) to ammonia (NH₃ ) is always achieved in alkali, the selectivity dependence on nitrogen (N₂ ) protonation and mechanisms therein are unrevealed. Herein, we profile how the NRR selectivity theoretically relies upon the first protonation that is collectively regulated by proton (H) abundance and adsorption-desorption, along with intermediate-*NNH formation. By incorporating electronic metal modulators (M=Co, Ni, Cu, Zn) in nitrogenase-imitated model-iron polysulfide (FeSx), a series of FeMSx catalysts with tailorable protonation kinetics are obtained. The key intermediates behaviors traced by in situ FT-IR and Raman spectroscopy and operando electrochemical impedance spectroscopy demonstrate the strong protonation kinetics-dependent selectivity that mathematically follows a log-linear Bradley curve. Strikingly, FeCuSx exhibits a record-high selectivity of 75.05 % at -0.1 V (vs. RHE) for NH₃ production in 0.1 M KOH electrolyte.

Keywords: Adjustable Protonation Kinetics; Electronic Modulation; Nitrogen Electroreduction; Operando Electrochemical Impedance Spectroscopy Simulations; Protonation-Selectivity Relation.

Abstract

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