Tuning the performance of nitrogen reduction reaction by balancing the reactivity of N2 and the desorption of NH3
Lijuan Niu, Dandan Wang, Kang Xu, Weichang Hao, Li An, Zhenhui Kang, Zaicheng Sun
Abstract
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.