Tuning the performance of nitrogen reduction reaction by balancing the reactivity of N₂ and the desorption of NH₃

Electrochemical reduction of nitrogen to ammonia under mild conditions provides an intriguing approach for energy conversion. A grand challenge for electrochemical nitrogen reduction reaction (NRR) is to design a superior electrocatalyst to obtain high performance including high catalytic activity and selectivity. In the NRR process, the three most important steps are nitrogen adsorption, nitrogen activation, and ammonia desorption. We take MoS₂ as the research object and obtain catalysts with different electronic densities of states through the doping of Fe and V, respectively. Using a combination of experiments and theoretical calculations, it is demonstrated that V-doped MoS₂ (MoS₂-V) shows better nitrogen adsorption and activation, while Fe-doped MoS₂ (MoS₂-Fe) obtains the highest ammonia yield in experiments (20.11 µg·h⁻¹·mg⁻¹cat.) due to its easier desorption of ammonia. Therefore, an appropriate balance between nitrogen adsorption, nitrogen activation, and ammonia desorption should be achieved to obtain highly efficient NRR electrocatalysts. [Figure not available: see fulltext.].