Systematic exploration of N, O coordination number on the catalytic performance for oxygen reduction and oxygen evolution

[Display omitted] •The N, O coordination number on ORR and OER catalytic activity is explored by DFT.•RhN3O1-1 and IrN3O1-1 have the excellent ORR catalytic activity.•Mulliken charge analysis can effectively reveal the origin of the activity. The reaction rate of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is an important factor restricting its application. In this work, we have systematic explorated of N, O coordination number on the catalytic performance for ORR and OER. Firstly, a variety of stability analysis methods show that most of the catalysts have excellent stability. Secondly, a series of excellent bifunctional catalysts are screened by volcanic maps, ORR overpotential (ηORR), OER overpotential (ηOER), and bifunctional index (BI), such as, RhN3O1-1 (ηORR = 0.28 V, ηOER = 0.34 V, BI = 0.62 V) and CoN3O1-1 (ηORR = 0.33 V, ηOER = 0.37 V, BI = 0.70 V). In particular, RhN3O1-1 has the smallest BI value, indicating that it has the best bifunctional catalytic activity. This study offers insights into how the coordination environment affects the activity of OER/ORR.