RuN₂ Monolayer: A Highly Efficient Electrocatalyst\nfor Oxygen Reduction Reaction

Abstract

The\ntransition metal-based nitride (TMN) holds great promise as\ncatalysts with high efficiency for energy-related technologies. Herein,\non the basis of global structure search and density functional theory\ncalculations, a novel two-dimensional (2D) TMN was identified: RuN₂ monolayer with tetracoordinated Ru atoms and isolated NN\ndimers, which is revealed to possess high thermal, dynamic, and chemical\nstabilities as well as metallic nature, thus providing great feasibility\nfor its practical application in electrochemical reactions. Remarkably,\nwe found that the predicted RuN₂ monolayer exhibits superior\ncatalytic performance for the oxygen reduction reaction (ORR) with\na rather high limiting potential (0.99 V) and an overwhelming four-electron\nreduction pathway selectivity. Thus, our results suggested the robust\napplicability of RuN₂ monolayer as a novel non-Pt catalyst\ndue to its excellent catalytic efficiency and outstanding selectivity\nfor ORR, which not only proposes a new member to the hypercoordinate\n2D TMN with novel properties, but also provides a feasible strategy\nto further develop novel TMN-based nanomaterials for electrocatalytic\nenergy conversion.