High-performance NH₃ production via NO electroreduction over a NiO nanosheet array

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Catalysis

Background:

• Nitrogen oxide (NO) emissions contribute to air pollution and acid rain.
• Electrocatalytic reduction offers a promising route for NO control and valuable chemical production.
• Developing efficient and selective electrocatalysts for NO reduction under ambient conditions is crucial.

Purpose of the Study:

• To develop a highly active and selective electrocatalyst for NO reduction.
• To investigate the performance of a NiO nanosheet array catalyst for NO to NH3 conversion.
• To explore the potential of a Zn-NO battery for simultaneous electricity generation and ammonia production.

Main Methods:

• Fabrication of NiO nanosheet arrays on titanium mesh.
• Electrochemical testing of the catalyst for NO reduction.
• Assembly and testing of an aqueous Zn-NO battery.
• Theoretical calculations to elucidate the NO electroreduction mechanism.

Main Results:

• The NiO nanosheet array achieved 90% faradaic efficiency for NO reduction.
• A high ammonia (NH3) yield of 2130 μg h⁻¹ cm⁻² was obtained.
• The Zn-NO battery demonstrated a power density of 0.88 mW cm⁻² and NH3 yield of 228 μg h⁻¹ cm⁻².
• Theoretical calculations provided insights into the reaction mechanism.

Conclusions:

• NiO nanosheet arrays are effective electrocatalysts for NO reduction to NH3.
• The developed Zn-NO battery system shows potential for energy generation and pollutant remediation.
• This work contributes to the development of sustainable technologies for emission control and chemical synthesis.