posted on 2022-12-16, 15:42authored byWanru Liao, Kang Liu, Jun Wang, Andrei Stefancu, Qin Chen, Kuangzhe Wu, Yajiao Zhou, Hongmei Li, Lin Mei, Ming Li, Junwei Fu, Masahiro Miyauchi, Emiliano Cortés, Min Liu
Electrocatalytic
N2 reduction reaction (eNRR) provides
a promising carbon-neutral and sustainable ammonia-synthesizing alternative
to the Haber-Bosch process. However, the nonpolar N2 has
significant thermodynamic stability and requires ultrahigh energy
to break down the NN bond. Here, we report the construction
of local enhanced electric fields (LEEFs) by Ag nanoneedle arrays
to promote NN fracture thus assisting the eNRR. The LEEFs
could induce charge polarization on nitrogen atoms and reduce the
energy barrier in the N2 first-protonation step. The detected
NN and NH intermediates prove the cleavage of the
NN bond and the hydrogenation of N2 by LEEFs. The
increased LEEFs lead to logarithmic growth rates for the targeted
eNRR and exponential growth rates for the unavoidable competitive
hydrogen evolution reaction. Thus, regulation and tuning of LEEFs
to ∼4 × 104 kV m–1 endows
the raise of eNRR to the summit, achieving high ammonia selectivity
with a Faradaic efficiency of 72.3 ± 4.0%.