Unusual electrochemical N-2 reduction activity in an earth-abundant iron catalyst via phosphorous modulation

Fe-enabled high-performance ambient electrochemical N-2 reduction still remains a big challenge. Here, we report the unusual role of phosphorous in modulating the electrochemical N-2 reduction activity of an Fe catalyst. An FeP2 nanoparticle-reduced graphene oxide hybrid (FeP2-rGO) attains a large NH3 yield of 35.26 mu g h(-1) mg(cat.)(-1) (7.06 mu g h(-1) cm(-2)) and a high faradaic efficiency of 21.99% at -0.40 V vs. reversible hydrogen electrode in 0.5 M LiClO4, outperforming the FeP-rGO hybrid (17.13 mu g h(-1) mg(cat.)(-1); 8.57%). Theoretical calculations reveal that FeP2 possesses decreased catalytic activity for the hydrogen evolution reaction, higher N-2 adsorption energy, and a larger number of active sites than FeP.