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

Abstract

The development of electrochemical nitrogen reduction reaction (NRR) catalysts with high catalytic activity and high stability is a significant challenge. In this work, a LaCu_0.1Fe_0.9O_3−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–O^2−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.