Enhanced electrocatalytic nitrogen reduction inspired by a lightning rod effect on urchin-like Co3O4 catalyst

The electrocatalytic nitrogen reduction reaction (ENRR) is a potential approach to environment-friendly produce NH3 under ambient conditions. However, the efficiency of ENRR is seriously limited by the extremely low solubility of N2 in electrolyte and the competitive hydrogen evolution reaction (HER) under high overpotential. Herein, we demonstrate that a deliberately designed urchin-like (U-L) Co3O4 electrocatalyst exhibits an enhanced ENRR performance with a promising Faradaic efficiency (FE) of 18.5 % and a high NH3 yield of 49.1 µg h−1 mgcat−1 in 0.5 M LiClO4. Experimental results and computational simulations prove that the high-curvature tips of U-L Co3O4 can generate a strong local electric field, which is similar to the "lightning rod effect" in nature. Consequently, the engineered strong local electric field effectively induces Li+ accumulation and correspondingly results in a high local concentration of N2 at the electrocatalyst surface. The strategy of local electric field enhanced electrochemical kinetic opens a new avenue to explore advanced electrocatalysts to promote the ENRR performance.