Enhanced N2 Adsorption and Activation by Combining Re Clusters and In Vacancies as Dual Sites for Efficient and Selective Electrochemical NH3 Synthesis

Abstract

The electrochemical N₂ reduction reaction (NRR) is a green and energy-saving sustainable technology for NH₃ production. However, high activity and high selectivity can hardly be achieved in the same catalyst, which severely restricts the development of the electrochemical NRR. In₂Se₃ with partially occupied p-orbitals can suppress the H₂ evolution reaction (HER), which shows excellent selectivity in the electrochemical NRR. The presence of V_In can simultaneously provide active sites and confine Re clusters through strong charge transfer. Additionally, well-isolated Re clusters stabilized on In₂Se₃ by the confinement effect of V_In result in Re-V_In active sites with maximum availability. By combining Re clusters and V_In as dual sites for spontaneous N₂ adsorption and activation, the electrochemical NRR performance is enhanced significantly. As a result, the Re-In₂Se₃-V_In/CC catalyst delivers a high NH₃ yield rate (26.63 μg h^-1 cm^-2) and high FEs (30.8%) at -0.5 V vs RHE.

Keywords: In vacancies; N2 activation; Re clusters; electrochemical NRR; p-block metal selenide.