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 N-2 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 mu g h(-l) mg(cat)(-1) in 0.5 M LiClO4. Experimental results and computational simulations prove that the high-curvature tips of U-LCo3O4 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 N-2 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.