High electrocatalytical performance of FeCoNiCuPd high-entropy alloy for nitrogen reduction reaction

To search excellent catalyst for electrocatalytic nitrogen reduction reaction (eNRR) is of great importance for the alternative to the traditional Haber-Bosch process. Herein, based on density functional theory (DFT) calculations, we systematically investigated the catalytic mechanism of eNRR on different-proportions high-entropy alloy (HEA) FeCoNiCuPd. The calculation of formation energy shown the dependence of structural stability on the ratio of constituents. Meanwhile, it is found that Ni0.3(FeCoCuPd)0.175 features high thermal stability. The Ni0.3(FeCoCuPd)0.175 with exposed crystal plane (111) exhibited excellent performance of eNRR with the lowest overpotential of 0.34 eV. Catalytically kinetic results demonstrated that Ni0.3(FeCoCuPd)0.175 follows the distal reaction pathway and the rate-determining step (RDS) was found to be *N2 →*NNH with the barrier of 0.50 eV. Relative to the secondary reaction of hydrogen evolution reaction (HER), such catalyst achieves the excellent selectivity of 99%. Detailed electronical calculations results indicated the connection between catalytic activity and d-band center, shedding light on the critical role of Ni element ratio in the catalytic performance.