Ambient N[tbnd]N bond weakening hydrogenation by utilizing the highly defective Cu3BiS3/MnO2 electrocatalyst for ammonia yield above 3 mg/h.cm2: The N2-nano dipole interaction micromechanism

Abstract

This study introduces a novel Cu3BiS3/MnO2 composite catalyst for the electrochemical nitrogen reduction reaction (eNRR) to address challenges in sustainable ammonia production, aiming to replace the energy-intensive Haber-Bosch process. The ternary Cu3BiS3/MnO2 catalyst exhibited impressive results, achieving a high ammonia yield rate of 3604 µg h−1cm−2 and a significant Faradaic efficiency of 31.4 % at −0.75 V vs. RHE in a 0.5 M Na2SO4 solution, while only 446 µg h−1cm−2 from binary metal CuMn(2:3). This success was attributed to abundant cation and anion defects with multiple valence charges in the Cu3-xBiS3/MnO2-y catalyst, created by introducing the third metal, Bi, into the binary CuMn system. These defects served as trapping centers for dynamic nitrogen molecule activation and facilitated charge transport, enhancing the eNRR process. This study underscores the potential of highly defective Cu3-xBiS3/MnO2-y as an efficient and sustainable catalyst for electrochemical nitrogen fixation, offering a greener approach to ammonia production.