Ammonia synthesis via a protonic ceramic electrolysis cell (PCEC) using LaCu0.1Fe0.9O3−δ catalyst

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 12; no. 2; pp. 1200 - 1210
• Main Authors: Guo, Wenhua, Li, Yawei, Si-Dian, Li, Shao, Zongping, Chen, Huili
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 03.01.2024
• Subjects: Ammonia; Catalysts; Catalytic activity; Chemical reduction; Electrocatalysts; Electrochemistry; Electrode materials; Electrolysis; Electron transfer; Electrons; Nitrogen; Perovskites; Stability; Synergistic effect
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d3ta04559e

The development of electrochemical nitrogen reduction reaction (NRR) catalysts with high catalytic activity and high stability is a significant challenge. In this work, a LaCu0.1Fe0.9O3−δ (LCuF) electrocatalyst for NRR was developed based on B-site Cu doping in the LaFeO3 (LF) perovskite. Good NRR catalytic performance and long-term stability were achieved when this catalyst was used as the cathode material for a protonic ceramic electrolysis cell (PCEC). Experimental results demonstrate that the synergistic effect between Cu and Fe enhances the NRR activity of this electrocatalyst. Electrons are transferred through the Fe–O2−δ–Cu chain, resulting in the formation of more Fe4+ at Fe sites and more Cu+ at Cu sites. This accelerates the electron transfer rate and thus increases the NRR rate. At the same time, more oxygen vacancies (OVs) are generated around Cu+. Fe4+ and OVs are both electron-deficient species, which are helpful for activating N2 by trapping metastable electrons in the anti-bonding orbitals of adsorbed nitrogen molecules. This work provides a viable strategy for developing a highly efficient NRR electrocatalyst.