Open AccessAn Efficient Symmetric Electrolyzer Based On Bifunctional Perovskite Catalyst for Ammonia Electrolysis
Author(s) -
Zhang Mengfei,
Li Hao,
Duan Xiuyun,
Zou Peimiao,
Jeerh Georgina,
Sun Boyao,
Chen Shigang,
Humphreys John,
Walker Marc,
Xie Kui,
Tao Shanwen
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202101299
Subject(s) - bifunctional , ammonia , electrolysis , catalysis , chemistry , inorganic chemistry , perovskite (structure) , bifunctional catalyst , ammonia production , oxide , chemical engineering , materials science , organic chemistry , electrode , engineering , electrolyte
Ammonia is a natural pollutant in wastewater and removal technique such as ammonia electro‐oxidation is of paramount importance. The development of highly efficient and low‐costing electrocatalysts for the ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) associated with ammonia removal is subsequently crucial. In this study, for the first time, the authors demonstrate that a perovskite oxide LaNi 0.5 Cu 0.5 O 3‐ δ after being annealed in Ar (LNCO55‐Ar), is an excellent non‐noble bifunctional catalyst towards both AOR and HER, making it suitable as a symmetric ammonia electrolyser (SAE) in alkaline medium. In contrast, the LNCO55 sample fired in air (LNCO55‐Air) is inactive towards AOR and shows very poor HER activity. Through combined experimental results and theoretical calculations, it is found that the superior AOR and HER activities are attributed to the increased active sites, the introduction of oxygen vacancies, the synergistic effect of B‐site cations and the different active sites in LNCO55‐Ar. At 1.23 V, the assembled SAE demonstrates ≈100% removal efficiency in 2210 ppm ammonia solution and >70% in real landfill leachate. This work opens the door for developments towards bifunctional catalysts, and also takes a profound step towards the development of low‐costing and simple device configuration for ammonia electrolysers.