Ambient Ammonia Synthesis via Electrochemical Reduction of Nitrate Enabled by NiCo2O4 Nanowire Array

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 18; no. 13
• Main Authors: Liu, Qian, Xie, Lisi, Liang, Jie, Ren, Yuchun, Wang, Yuanyuan, Zhang, Longcheng, Yue, Luchao, Li, Tingshuai, Luo, Yongsong, Li, Na, Tang, Bo, Liu, Yang, Gao, Shuyan, Alshehri, Abdulmohsen Ali, Shakir, Imran, Agboola, Philips O., Kong, Qingquan, Wang, Qingyuan, Ma, Dongwei, Sun, Xuping
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-04-2022
• Subjects: Ammonia; ammonia electrosynthesis; Arrays; Catalytic activity; Chemical reduction; Crystal structure; density functional theory; electrocatalysis; Electrocatalysts; Nanotechnology; Nanowires; Nickel compounds; NiCo 2O 4 nanowire arrays; nitrate reduction reaction
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.202106961

NiCo2O4 nanowire array on carbon cloth (NiCo2O4/CC) is proposed as a highly active electrocatalyst for ambient nitrate (NO3−) reduction to ammonia (NH3). In 0.1 m NaOH solution with 0.1 m NaNO3, such NiCo2O4/CC achieves a high Faradic efficiency of 99.0% and a large NH3 yield up to 973.2 µmol h−1 cm−2. The superior catalytic activity of NiCo2O4 comes from its half‐metal feature and optimized adsorption energy due to the existence of Ni in the crystal structure. A Zn‐NO3− battery with NiCo2O4/CC cathode also shows a record‐high battery performance.
NiCo2O4 nanowire array on carbon cloth is an efficient electrocatalyst for NO3− to NH3 conversion under ambient conditions, achieving a high Faradic efficiency of 99.0% and a large NH3 yield up to 973.2 µmol h−1 cm−2 in 0.1 m NaOH with 0.1 m NO3−. The catalytic mechanism is investigated by theoretical calculations.