Screening of Intermetallic Compounds Based on Intermediate Adsorption Equilibrium for Electrocatalytic Nitrate Reduction to Ammonia.

Electrocatalytic nitrate (NO) reduction reaction (NORR) holds great potential for the conversion of NO contaminants into valuable NH in a sustainable method. Unfortunately, the nonequilibrium adsorption of intermediates and sluggish multielectron transfer have detrimental impacts on the electrocatalytic performance of the NORR, posing obstacles to its practical application. Herein, we initially screen the adsorption energies of three key intermediates, i.e., *NO, *NO, and *HO, along with the d-band centers on 21 types of transition metal (IIIV and IB)-Sb/Bi-based intermetallic compounds (IMCs) as electrocatalysts. The results reveal that hexagonal CoSb IMCs possess the optimal adsorption equilibrium for key intermediates and exhibit outstanding electrocatalytic NORR performance with a Faradaic efficiency of 96.3%, a NH selectivity of 89.1%, and excellent stability, surpassing the majority of recently reported NORR electrocatalysts. Moreover, the integration of CoSb IMCs/C into a novel Zn-NO battery results in a high power density of 11.88 mW cm.