Biomimetic Design of a Dynamic M–O–V <i>Pyramid</i> Electron Bridge for Enhanced Nitrogen Electroreduction

Abstract

Electrochemical nitrogen reduction reaction (eNRR) offers a sustainable route for ammonia synthesis; however, current electrocatalysts are limited in achieving optimal performance within narrow potential windows. Herein, inspired by the heliotropism of sunflowers, we present a biomimetic design of Ru-VOH electrocatalyst, featuring a dynamic Ru–O–V pyramid electron bridge for eNRR within a wide potential range. In situ spectroscopy and theoretical investigations unravel the fact that the electrons are donated from Ru to V at lower overpotentials and retrieved at higher overpotentials, maintaining a delicate balance between N 2 activation and proton hydrogenation. Moreover, N 2 adsorption and activation were found to be enhanced by the Ru–O–V moiety. The catalyst showcases an outstanding Faradaic efficiency of 51.48% at −0.2 V (vs RHE) with an NH 3 yield rate exceeding 115 μg h –1 mg –1 across the range of −0.2 to −0.4 V (vs RHE), along with impressive durability of over 100 cycles. This dynamic M–O–V pyramid electron bridge is also applicable to other metals (M = Pt, Rh, and Pd).