Chlorine-doped carbon for electrocatalytic nitrogen reduction

Abstract The electrochemical reduction of stable dinitrogen (N2) molecules into value-added chemicals such as ammonia has been attracting substantial research interests recently, while the bottleneck of catalyst design exists in the rational synthesis of catalytic centers with efficient N2 chemisorption and subsequent activation. In this work, we demonstrated a facile approach of doping carbon black with a trace amount of chlorine, which allowed for the enhancement of its nitrogen reduction capability. Structural characterizations revealed the successful doping of the chlorine element into the carbon framework, accompanied by the polarization of the surface charge density. The positively charged carbon sites behaved as good NRR catalytic centers, with a maximum ammonia production rate of 4.3 μg h−1 cm–2 and a corresponding Faradaic efficiency of 7.2%, thus suggesting a potential approach for enhancing the nonmetal catalysts for electrochemical ammonia synthesis.