Nitrogen (N), Phosphorus (P)-Codoped Porous Carbon as a Metal-Free Electrocatalyst for N2 Reduction under Ambient Conditions

The electrocatalytic conversion of nitrogen gas at ambient conditions represents a novel approach for ammonia synthesis to the sustainable society. It is critical to understand the detailed pathways and mechanisms of this promising process to develop a highly efficient catalyst. Herein, the N, P co-doping carbon (NP-C-MOF-5) catalyst was prepared for electrocatalytic N2 reduction in acid electrolytes under ambient temperatures and pressures. Experimental results showed that there are two products including NH3 and N2H4·H2O on the NP-C-MOF-5 cathode at −0.1 V versus RHE with the yield of 1.08 and 5.77 × 10–4 μg h–1 mgcat.–1, respectively. Moreover, an electrocatalytic pathway on NP-C-MOF-5 was investigated by the electrochemical in situ Fourier transform infrared technique. The results confirmed the formation of N2Hy (1 ≤ y ≤ 4) intermediates on NP-C-MOF-5 cathode surfaces, suggesting an associative pathway for the N2 reduction reaction.