Lithium-mediated electrochemical nitrogen reduction: Mechanistic insights to enhance performance

Xiyang Cai; Cehuang Fu; Haldrian Iriawan; Fan Yang; Aiming Wu; Liuxuan Luo; Shuiyun Shen; Guanghua Wei; Yang Shao-Horn; Junliang Zhang

iScience (Oct 2021)

Lithium-mediated electrochemical nitrogen reduction: Mechanistic insights to enhance performance

Xiyang Cai,
Cehuang Fu,
Haldrian Iriawan,
Fan Yang,
Aiming Wu,
Liuxuan Luo,
Shuiyun Shen,
Guanghua Wei,
Yang Shao-Horn,
Junliang Zhang

Affiliations

Xiyang Cai: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Cehuang Fu: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Haldrian Iriawan: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Materials, Imperial College London, London SW7 5RB, UK
Fan Yang: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Aiming Wu: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Liuxuan Luo: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Shuiyun Shen: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Guanghua Wei: SJTU-Paris Tech Elite Institute of Technology, Shanghai Jiao Tong University, Shanghai 200240, China
Yang Shao-Horn: Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Corresponding author
Junliang Zhang: Institute of Fuel Cells, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Corresponding author

Journal volume & issue: Vol. 24, no. 10
p. 103105

Abstract

Read online

Summary: Green synthesis of ammonia by electrochemical nitrogen reduction reaction (NRR) shows great potential as an alternative to the Haber-Bosch process but is hampered by sluggish production rate and low Faradaic efficiency. Recently, lithium-mediated electrochemical NRR has received renewed attention due to its reproducibility. However, further improvement of the system is restricted by limited recognition of its mechanism. Herein, we demonstrate that lithium-mediated NRR began with electrochemical deposition of lithium, followed by two chemical processes of dinitrogen splitting and protonation to ammonia. Furthermore, we quantified the extent to which the freshly deposited active lithium lost its activity toward NRR due to a parasitic reaction between lithium and electrolyte. A high ammonia yield of 0.410 ± 0.038 μg s−1 cm−2 geo and Faradaic efficiency of 39.5 ± 1.7% were achieved at 20 mA cm−2 geo and 10 mA cm−2 geo, respectively, which can be attributed to fresher lithium obtained at high current density.

Published in iScience

ISSN: 2589-0042 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Science
Website: http://www.cell.com/iscience/home

About the journal

Abstract

Keywords