Enhanced NH3 Synthesis from Air in a Plasma Tandem-Electrocatalysis System Using Plasma-Engraved N-Doped Defective MoS2

Jiageng Zheng; Hao Zhang; Jiabao Lv; Meng Zhang; Jieying Wan; Nick Gerrits; Angjian Wu; Bingru Lan; Weitao Wang; Shuangyin Wang; Xin Tu; Annemie Bogaerts; Xiaodong Li

doi:10.1021/jacsau.3c00087

Enhanced NH₃ Synthesis from Air in a Plasma Tandem-Electrocatalysis System Using Plasma-Engraved N-Doped Defective MoS₂

JACS Au. 2023 Apr 26;3(5):1328-1336. doi: 10.1021/jacsau.3c00087. eCollection 2023 May 22.

Authors

Jiageng Zheng¹, Hao Zhang¹, Jiabao Lv¹, Meng Zhang², Jieying Wan¹, Nick Gerrits³, Angjian Wu¹, Bingru Lan¹, Weitao Wang⁴, Shuangyin Wang⁵, Xin Tu⁴, Annemie Bogaerts³, Xiaodong Li¹

Affiliations

¹ State Key Laboratory of Clean Energy Utilization, College of Energy and Engineering, Academy of Ecological Civilization, Zhejiang University, Hangzhou 310027, China.
² College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
³ Research Group PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, BE-2610 Wilrijk, Belgium.
⁴ Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ, U.K.
⁵ State Key Laboratory of Chem/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.

Abstract

We have developed a sustainable method to produce NH₃ directly from air using a plasma tandem-electrocatalysis system that operates via the N₂-NO_x-NH₃ pathway. To efficiently reduce NO₂^- to NH₃, we propose a novel electrocatalyst consisting of defective N-doped molybdenum sulfide nanosheets on vertical graphene arrays (N-MoS₂/VGs). We used a plasma engraving process to form the metallic 1T phase, N doping, and S vacancies in the electrocatalyst simultaneously. Our system exhibited a remarkable NH₃ production rate of 7.3 mg h^-1 cm^-2 at -0.53 V vs RHE, which is almost 100 times higher than the state-of-the-art electrochemical nitrogen reduction reaction and more than double that of other hybrid systems. Moreover, a low energy consumption of only 2.4 MJ mol_NH₃^-1 was achieved in this study. Density functional theory calculations revealed that S vacancies and doped N atoms play a dominant role in the selective reduction of NO₂^- to NH₃. This study opens up new avenues for efficient NH₃ production using cascade systems.