Electrocatalytic reduction of nitrogen on FeAg/Si for ammonia synthesis: A simple strategy for continuous regulation of faradaic efficiency by controlling H+ ions transfer rate

Abstract

Electrocatalytic nitrogen reduction offers a dream way to produce active nitrogen for agriculture and high-energy-dense carbon-free fuels for our blue planet. However, it suffers from extremely low faradaic efficiency values, because the conversion rate is greatly limited by the competing hydrogen reduction reaction, seeking for a new strategy to solve the bottleneck problem is highly desirable. Herein, it is found that H+ ions transfer rate can be linearly regulated by tuning the pore numbers of the membrane in an H-type cell, while the Faradaic efficiency can be continuously regulated in the same way. Meanwhile, a physical model has been constructed to reveal the changing mechanism of the Faradaic efficiency. The theoretical results well agree with the experimental ones obtained by the synthetic plasma-enhanced bimetallic catalyst (FeAg nanoclusters dispersed on Si nanowire). In this study we achieved a continuous enhancement of the Faradaic efficiency from 9.04 % to 41.86 %.