Ambient Electrosynthesis of Ammonia on a Biomass-Derived Nitrogen-Doped Porous Carbon Electrocatalyst: Contribution of Pyridinic Nitrogen

By Cuijiao Zhao, Shengbo Zhang, Miaomiao Han, Xian Zhang, Yanyan Liu, Wenyi Li, Chun Chen, Guozhong Wang, Haimin Zhang, Huijun Zhao. ACS Energy Letters, 2019

147 citations recorded by the source corpus.

Here we report that alfalfa-derived nitrogen-doped porous carbon (NPC) fabricated by a pyrolysis method is electrochemically active for the N2 reduction reaction (NRR) at ambient conditions. The results demonstrate that the obtained NPC material with a nitrogen content of 6.35 atom % at 500 °C (NPC-500) exhibits high NRR activity with an NH3 yield rate of 1.31 mmol h–1 g–1cat. and a Faradaic efficiency of 9.98% at −0.4 V (vs RHE) in 0.005 M H2SO4 solution. The isotopic labeling experimental results using 15N2 feed gas and 15NPC-500 reveal that the yielded NH3 indeed resulted from the NPC-500 catalyzed NRR, and the doped pyridinic-N also contributes NH3 formation during NRR. The experimental and theoretical calculations results indicate that the doped pyridinic-N in the NPC catalyst during NRR can break away from its surface to form N vacancies in a carbon matrix as the catalytic active sites for N2 adsorption and activation.

View Paper: https://www.semanticscholar.org/paper/428bae772684bd793118ec9bdfd9956c3e0b7dfe