Synergistic multi-adsorption of N2 on MoS2 supported single metal atoms: Enhancing electroreduction of nitrogen to ammonia

Abstract

MoS2-supported transition metal single atom (TM/MoS2) is expected to exhibit good performance in N2 reduction reaction (NRR). Based on systematically investigations of the stability and potential electrocatalytic nitrogen reduction reaction (NRR) performance of 27 types of TM/MoS2, V(Nb, Ta)/MoS2 exhibit good structure stability, excellent N2 activity and high ammonia (NH3) selectivity. Three nitrogen molecules are effectively captured on V(Nb, Ta)/MoS2 and the multi-adsorption of nitrogen make Mo-top site energy favorable for all the *3N2–V(Nb, Ta)/MoS2 especially for *3N2–Nb/MoS2 the energy favorable sites shift from hollow site to Mo-top site. The NRR proceeds via distal pathway, along which the limiting potentials are calculated to be −0.55, −0.42, −0.34 V for V/MoS2, Nb/MoS2 and Ta/MoS2, respectively. The transformation of Nb/MoS2 and the multi-adsorption of *N2 make the *N2 more negatively charged and more effectively activated than single adsorbed *N2, meanwhile suppressing the production of hydrogen. This work also shows the coordination difference with and without reactants adsorption and the impact on catalytic performance, which raises the importance of considering the stability of intermediates along reaction paths during theoretical design of new catalysts.