Cascade N₂ Reduction Process with DBD Plasma Oxidation and Electrocatalytic Reduction for Continuous Ammonia...

Area of Science:

• Chemical Engineering
• Plasma Chemistry
• Electrochemistry

Background:

• The Haber-Bosch process for ammonia synthesis is energy-intensive and a major source of CO2 emissions.
• The high N≡N bond energy necessitates harsh conditions for traditional ammonia production.

Purpose of the Study:

• To propose and evaluate a novel cascade nitrogen reduction process combining nonthermal plasma oxidation and electrocatalytic reduction.
• To demonstrate a sustainable and energy-efficient alternative route for ammonia synthesis.

Main Methods:

• Utilizing dielectric barrier discharge (DBD) plasma to oxidize N2 into reactive nitrogen species (RNS).
• Absorbing RNS in KOH solution and electroreducing them to ammonium (NH4+).
• Employing a cobalt catalyst for enhanced electrocatalytic reduction of ammonia.

Main Results:

• Optimized NO production based on discharge parameters (length, power, flow rate).
• Achieved high selectivity (Faradic efficiency >90%) and ammonia yield (45.45 mg/h) using a cobalt catalyst.
• Demonstrated a stable ammonia production rate of 16.21 mg/h with 22.16% conversion of activated NO to NH4+.

Conclusions:

• The proposed cascade plasma oxidation and electrocatalytic reduction is a viable alternative for ammonia synthesis.
• This method shows potential for industrial application, offering reduced energy consumption and CO2 footprint.
• Further research can optimize the system for even higher efficiency and broader industrial adoption.