First-principles study of two-dimensional material Cr2B2 as catalyst for electrochemical nitrogen reduction reaction

• The catalytic performance of Cr 2 B 2 for NRRby using DFT method. • There is an excellent NRR catalytic activity when N 2 adsorbed Cr-B bond. • The limiting potential can be reduced by N N breaking to acquire better NRR performance. Electrochemical nitrogen reduction reaction (NRR) is becoming increasingly promising alternatively to the traditional Haber-Bosch process but developing efficient electrocatalysts is still a challenge. In this job, we searched that the catalytic performance of Cr 2 B 2 for NRR by way of density functional theory (DFT) calculations. We mainly screened out four favorable N 2 adsorbed structures, including N 2 adsorption on the B-B bonds, Cr-B bonds, top site of B and Cr atom. It was found that the largest adsorption energy was −1.235 eV when N 2 was adsorbed on the Cr-B bond in a side-on structure, and has a better excellent NRR catalytic activity with the limiting potential is 0.29 V. The catalytic activity of all structures was better in the alternating mechanism of nitrogen reduction reaction. As the antibonding orbitals approach the Fermi level, the number of electrons in the antibonding orbitals increases. The limiting potential of T Cr _end can also be reduced from 0.88 V to 0.35 V by N N bond breaking after the second hydrogen, which contribute to the greater NRR performance. We hope that this research will offer a viable strategy for the design of NRR catalysts, and offer a new way of thinking for MBene as a catalyst for NRR.