S-Doped Carbon Nanospheres: An Efficient Electrocatalyst toward Artificial N2 Fixation to NH3

Industrial NH3 synthesis mainly relies on the carbon-emitting Haber-Bosch process operating under severe conditions. Electrocatalytic N-2 to NH3 fixation at ambient conditions is an attractive approach to reduce energy consumption and avoid direct carbon emission. In this communication, it is reported that the S-doped carbon nanosphere (S-CNS) acts as an efficient and stable nitrogen reduction reaction (NRR) catalyst for ambient N-2 to NH3 conversion with excellent selectivity. In 0.1 M Na2SO4, the S-CNS achieves a large NH3 yield of 19.07 mu g h(-1)mg(cat)(-1) and a high Faradic efficiency of 7.47% at -0.7 V versus reversible hydrogen electrode, much higher than those of undoped CNS (3.70 mu g h(-1)mg(cat,)(-1) 1.45%). Notably, this catalyst also demonstrates high electrochemical and structure stability.