Effectively boosting selective ammonia synthesis on electron-deficient surface of MoB2

Abstract

Carbon-free electrocatalytic nitrogen reduction reaction (NRR) is an attractive replacement of the current Haber-Bosch method. However, there is a lack of suitable electrocatalysts that simultaneously achieve both high activity and selectivity, hindering the practical applications of NRR. Herein we theoretically design an electron-deficient surface of MoB2 for preferential N2 adsorption and thus increase the local concentration of N2 around the active sites. These lead to outstanding NRR selectivity that can evidently retard the competing HER even at the NRR operating potential. The corresponding theoretical limiting potential for NRR is as low as − 0.34 V. Our proof-of-concept experiment confirms the above theoretical design, in which excellent NRR performances (NH3 yield rate of ~ 40.94 μg h−1 mg−1, FE of ~ 30.84%) have been achieved. The strategy of inducing electron deficiency on active sites provides new insight into the rational design of NRR electrocatalysts for realizing green and effective ammonia synthesis in practical applications.