High single-pass conversion of nitrous oxide to dinitrogen in gas-diffusion-electrolyzer

Area of Science:

• Environmental Science
• Catalysis
• Electrochemistry

Background:

• Nitrous oxide (N₂O) is a potent greenhouse gas with significant environmental impact.
• Electrocatalytic N₂O reduction offers a sustainable pathway for N₂O mitigation under ambient conditions.
• Achieving high single-pass conversion efficiency in N₂O electrocatalytic reduction remains a key challenge.

Purpose of the Study:

• To develop an efficient electrocatalytic system for N₂O reduction.
• To investigate the performance of a copper-silver bimetallic nanoalloy catalyst.
• To assess the techno-economic viability of the proposed N₂O decomposition method.

Main Methods:

• Design and implementation of a gas-diffusion electrolyzer system.
• Utilization of copper-silver (Cu-Ag) bimetallic nanoalloy as the electrocatalyst.
• Employing computational fluid dynamics (CFD) for system optimization.
• Conducting techno-economic assessment for cost analysis.

Main Results:

• Achieved a single-pass conversion rate of 79.4% for 10 vol.% N₂O.
• Obtained a high N₂O decomposition rate of 1381.7 μmol h⁻¹ mg⁻¹.
• CFD simulations revealed optimized gas flow and reduced diffusion distances, ensuring uniform N₂O distribution.
• Cu-Ag synergy effectively facilitated N₂O adsorption, hydrogenation, and N-O bond cleavage.

Conclusions:

• The developed gas-diffusion electrolyzer system with Cu-Ag nanoalloy catalyst demonstrates high efficiency for N₂O electrocatalytic reduction.
• The system shows substantial potential and practical viability for N₂O decomposition.
• The levelized N₂O decomposition cost is estimated between 1.66-2.14 US$ kg⁻¹, indicating economic feasibility.