Curvature-programmed nitrate electroreduction via single-atom protrusions on quantum dots

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Local geometric constraints significantly impact electronic structure and catalyst performance.
• Conventional single-atom catalysts (SACs) often use planar sites, limiting their potential.
• Three-dimensional catalyst configurations offer underexplored opportunities for enhanced activity.

Purpose of the Study:

• To introduce a "curvature-programming" strategy for designing advanced single-atom catalysts.
• To investigate the electrochemical nitrate reduction performance of FeCu dual single-atom protrusions on molybdenum carbide quantum dots (FeCu/MoC_x-5 QDs).
• To explore the potential of 3D catalyst architectures for environmental remediation and energy storage.

Main Methods:

• Synthesized FeCu dual single-atom protrusions on molybdenum carbide quantum dots (FeCu/MoC_x-5 QDs).
• Employed a "curvature-programming" strategy to create high-curvature quantum dots with protruding geometries.
• Evaluated the electrochemical nitrate reduction activity, Faradaic efficiency, overpotential, and energy consumption of the catalyst.

Main Results:

• FeCu/MoC_x-5 QDs demonstrated nearly 100% NH₃ Faradaic efficiency over a wide potential window (-0.1 to -0.4 V vs. RHE).
• Achieved an ultralow overpotential of 300 mV and energy consumption of 7.52 Wh g_NH3^-1 mg_cat^-1.
• The catalyst effectively reduced nitrate in wastewater and produced scalable ammonium sulfate.

Conclusions:

• The "curvature-programming" strategy successfully enhances single-atom catalyst performance by mimicking active vertex sites.
• FeCu/MoC_x-5 QDs offer a highly efficient and stable catalyst for electrochemical nitrate reduction.
• This approach integrates environmental remediation with renewable energy storage, paving the way for broader energy applications of SACs.