Highly amorphized nickel-based ternary metal catalysts for efficient urea oxidation reaction

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Urea oxidation reaction (UOR) is crucial for sustainable energy technologies.
• Transient loss of high-valence Nickel (Ni) active sites limits UOR kinetics.
• Developing stable and efficient catalysts is essential to overcome these limitations.

Purpose of the Study:

• To synthesize novel transition metal (M = Mn, Co, Fe)-doped NiMoO4 amorphized electrodes (NiMoO4/M) for enhanced UOR.
• To investigate the role of amorphization and synergistic effects in improving catalytic activity.
• To provide a strategic framework for designing efficient multi-metallic UOR catalysts.

Main Methods:

• Two-step hydrothermal synthesis of M-doped NiMoO4 amorphized electrodes.
• Electrochemical characterization to evaluate catalytic performance (current density, overpotential).
• Analysis of electronic and structural properties to understand catalytic mechanisms.

Main Results:

• NiMoO4/Mn demonstrated superior stability and selectivity, achieving 100 mA cm-2 at 1.48 V vs. RHE.
• Amorphized surface structure and synergistic Ni-Mo-M effects significantly improved catalytic activity.
• Electrochemical reconstruction formed ternary Ni-Mo-M active sites, with Mo regulating Ni's electronic configuration.
• Doped metals enhanced Mo's electron-accepting ability, optimizing electron transfer and UOR kinetics.

Conclusions:

• Amorphized NiMoO4 doped with transition metals offers a promising pathway for efficient UOR catalysis.
• Synergistic electronic interactions between Ni, Mo, and dopant metals are key to high performance.
• This approach provides a strategy for designing advanced electrocatalysts by tuning electronic and structural properties.