Metal (Co/Mo)–N bond anchor-doped N in porous carbon for electrochemical nitrogen reduction

Abstract

Currently, nitrogenous electrocatalysts (particularly, nitrogen (N)-doped carbon materials) have attracted extensive attention owing to their superior electrochemical nitrogen reduction reaction (NRR) performances. Unfortunately, doped nitrogen atoms could directly contribute to the formation of ammonia via dissociation and hydrogenation. Significantly, the type of N atoms (pyrrolic-N, pyridinic-N, or graphitic-N) in N-doped carbon donated to NH₃ formation still needs to be verified. Here, using chitosan-derived N-doped porous carbon as an NRR electrocatalyst, we demonstrated that pyrrolic-N and pyridinic-N could disaggregate and hydrogenate to form NH₃, leading to the increase in the yield of ammonia. To remedy this issue, metal–N bonds as an efficient and universal strategy were proposed to anchor doped N in porous carbon for NRR. Specifically, Co (Mo) atoms coordinated with N atoms could not only effectively inhibit the disaggregation of doped N atoms but also successfully promote the electrocatalytic NRR activity, thus yielding a boosted NRR performance.