Identification of new effective and selective N-2 reduction electrocatalyst is still of critical importance for fundamental and application research. Here, we report La2O3 nanoplate performing as an efficient metal oxide catalyst for electrochemical N-2 fixation to NH3, which exhibits excellent selectivity and stability with a high Faradaic efficiency of 4.76% and a NH3 yield rate of 17.04 mu g h(-1) mg(cat.)(-1) at -0.8 V vs. reversible hydrogen electrode (RHE) in 0.1 M Na2SO4 solution under atmospheric pressure. Density functional theory (DFT) calculation results show that La atoms in La2O3 act as the active sites for efficiently adsorbing N-2. The optimal adsorption approach of N-2 molecule on the (011) face of La2O3 is end-on-two configuration which is highly activated. Thus La2O3 exhibits high performance for electrochemical reduction of N-2. (C) 2018 Elsevier Ltd. All rights reserved.