High-selectivity electrocatalytic ammonia oxidation on Mo single-atom catalysts supported on BP@ZrC

Abstract

The efficiency of electrochemical ammonia oxidation is severely limited by its selectivity, and current designs of electrochemical ammonia oxidation reaction catalysts lack targeted research on the structure–activity relationship. In this work, transition metal single-atom catalysts were constructed based on BP@ZrC substrates, and the thermodynamic stability and catalytic activity of the catalyst were systematically investigated through density functional theory calculations. The first-principles calculations demonstrated that the designed catalyst structure could effectively inhibit the nitrogen–oxygen coupling side reaction. According to the volcano plot, Mo-BP@ZrC was selected as the optimal catalyst, with a low theoretical overpotential of 0.49 V and 100% selectivity for N₂. By comparing catalysts with different substrates and doping atoms, the activation mechanism of key intermediate NH₂* was analyzed. The revealed regularity in the density of states and a clear structure–activity relationship were found for designing electrochemical ammonia oxidation reaction catalysts. This work provides high-performance candidate catalysts for the electrochemical ammonia oxidation reaction and also offers a theoretical foundation for developing efficient electrochemical reaction catalysts.