1 research outputs found
Electrochemical Synthesis of NH<sub>3</sub> at Low Temperature and Atmospheric Pressure Using a γ‑Fe<sub>2</sub>O<sub>3</sub> Catalyst
The
electrochemical synthesis of NH<sub>3</sub> by the nitrogen
reduction reaction (NRR) at low temperature (<65 °C) and atmospheric
pressure using nanosized γ-Fe<sub>2</sub>O<sub>3</sub> electrocatalysts
were demonstrated. The activity and selectivity of the catalyst was
investigated both in a 0.1 M KOH electrolyte and when incorporated
into an anion-exchange membrane electrode assembly (MEA). In a half-reaction
experiment conducted in a KOH electrolyte, the γ-Fe<sub>2</sub>O<sub>3</sub> electrode presented a faradaic efficiency of 1.9% and
a weight-normalized activity of 12.5 nmol h<sup>–1</sup> mg<sup>–1</sup> at 0.0 V<sub>RHE</sub>. However, the selectivity
toward N<sub>2</sub> reduction decreased at more negative potentials
owing to the competing proton reduction reaction. When the γ-Fe<sub>2</sub>O<sub>3</sub> nanoparticles were coated onto porous carbon
paper to form an electrode for a MEA, their weight-normalized activity
for N<sub>2</sub> reduction was found to increase dramatically to
55.9 nmol h<sup>–1</sup> mg<sup>–1</sup>. However, the
weight- and area-normalized N<sub>2</sub> reduction activities of
γ-Fe<sub>2</sub>O<sub>3</sub> decreased progressively from 35.9
to 14.8 nmol h<sup>–1</sup> mg<sup>–1</sup> and from
0.105 to 0.043 nmol h<sup>–1</sup> cm<sup>–2</sup><sub>act</sub>, respectively, during a 25 h MEA durability test. In summary,
a study of the fundamental behavior and catalytic activity of γ-Fe<sub>2</sub>O<sub>3</sub> nanoparticles in the electrochemical synthesis
of NH<sub>3</sub> under low temperature and pressure is presented