DFT study of Ru/graphene as high-performance electrocatalyst for NRR.

• Mechanism of NRR occurred on Ru/graphene catalysts were studied by DFT. • The effects of Ru atom numbers and Ru atom distribution on Ru/Gr were studied. • Provide guidance for the design and preparation of NRR catalysts. As a more common catalyst material in nitrogen reduction reactions (NRR), Ru has high activity and considerable catalytic performance, but it is expensive with scarce reserves. These factors limit the development of Ru in NRR, how to reduce costs and increase the utilization of precious metals is a problem facing the development of Ru-based catalysts. Graphene is considered as a promising carrier material, which can increase the specific surface area and dispersibility of the catalyst, thereby improving the utilization rate of materials. Therefore we combined these two materials and studied the mechanism of NRR occurred on Ru/graphene (Gr) catalysts by density functional theory (DFT) method. The effects of different numbers of Ru atoms and Ru atom distribution on the catalytic activity of Ru/Gr catalyst were calculated. A series of data such as the adsorption free energy and reaction path were obtained. The final results show that the double Ru supported graphite nitrogen doped Gr with single adsorption process and the three Ru supported pyrrole nitrogen doped Gr with double adsorption process have the best NRR activity. Compared with catalyst-free process, the presence of the catalyst effectively reduces the reaction energy barrier and improves the reaction activity. The research results provide guidance for the design and preparation of high-performance NRR catalysts to a certain extent. [ABSTRACT FROM AUTHOR]