Binary Metal-Oxide Active Sites Derived from Cu-Doped MIL-88 with Enhanced Electroactivity for Nitrate Reduction

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Science

Background:

• Nitrate-to-ammonia conversion is crucial for water remediation and ammonia synthesis.
• Challenges exist in achieving high ammonium yield without byproducts.

Purpose of the Study:

• To develop efficient cathode materials for selective electrochemical nitrate-to-ammonium conversion.
• To investigate the role of Cu-doped bimetallic oxides in enhancing catalytic performance.

Main Methods:

• Fabrication of Cu-doped MIL-88-derived bimetallic oxide catalysts.
• Electrochemical characterization including Tafel slope analysis.
• Evaluation of ammonia yield and cathode efficiency over multiple cycles.

Main Results:

• Developed catalysts feature Fe-O-Cu bridges facilitating nitrate adsorption and hydrogenation.
• Achieved high ammonia yield (1698.8 μg·h^-1·cm^-2) with a low Tafel slope (62.1 mV dec^-1).
• Demonstrated stable cathode efficiency over seven cycles, with Cu doping inhibiting hydrogen evolution.

Conclusions:

• Cu-doped bimetallic oxides are promising for selective electrochemical nitrate reduction to ammonia.
• The study offers insights into designing novel interfaces for efficient electrocatalysis.
• This work opens avenues for advanced cathode materials in environmental applications.