Rational design of bimetallic MBene for efficient electrocatalytic nitrogen reduction

Electrocatalytic nitrogen reduction reaction (NRR) is one of the most promising approaches to achieving green and efficient NH₃ production. However, the designs of efficient NRR catalysts with high activity and selectivity still are severely hampered by inherent linear scaling relations among the adsorption energies of NRR intermediates. Herein, the properties of ten M₃B₄ type MBenes have been initially investigated for efficient N₂ activation and reduction to NH₃via first-principles calculations. We highlight that Cr₃B₄ MBene possesses remarkable NRR activity with a record-low limiting potential (-0.13 V). Then, this work proposes descriptor-based design principles that can effectively evaluate the catalytic activity of MBenes, which have been further employed to design bimetallic M₂M'B₄ MBenes. As a result, 5 promising candidates including Ti₂YB₄, V₂YB₄, V₂MoB₄, Nb₂YB₄, and Nb₂CrB₄ with excellent NRR performance have been extracted from 20 bimetallic MBenes. Further analysis illuminates that constructing bimetallic MBenes can selectively tune the adsorption strength of NHNH₂** and NH₂NH₂**, and break the linear scaling relations between their adsorption energies, rendering them ideal for NRR. This work not only pioneers the application of MBenes as efficient NRR catalysts but also proposes rational design principles for boosting their catalytic performance.