Conversion of dinitrogen to ammonia by rhenium doped graphyne

Abstract

Developing efficient catalysis for dinitrogen (N2) fixation is a very important and challenging issue in chemistry. Herein, by means of density functional theory (DFT) computations, we reported that the potential of single-atom Rhenium (Re) supported on the graphyne (Re-GY) for activating N2 and reducing it into ammonia (NH3). It is found that the adsorption energies of N2 on Re-GY for end-on/side-on configuration are −1.05/-0.56 eV, together with the N–N bond length are stretched to 1.14/1.21 Å, respectively. The hydrazine intermediate is difficult to release with adsorption energies of −1.71/1.49 eV on Re-GY for different pathways, which ensures it is sequentially hydrogenated and eventually form NH3. All the mechanisms considered are energetically favorable and the most favorable pathway is the mixed mechanism. It is worth noting that there are relatively rare researches on Re-based catalysts for N2 fixation, our findings provide a new option for the design and synthesis of catalysts for N2 reduction reaction.