Atomically Ordered PdCu Electrocatalysts for Selective and Stable Electrochemical Nitrate Reduction

Area of Science:

• Environmental Science
• Materials Science
• Electrochemistry

Background:

• Nitrate pollution in groundwater is a significant environmental concern.
• Electrochemical nitrate reduction (NO₃ RR) is an emerging technology for water remediation.

Purpose of the Study:

• To investigate the impact of structural ordering in PdCu alloy electrocatalysts on NO₃ RR performance.
• To develop stable and selective electrocatalysts for efficient nitrate removal.

Main Methods:

• Synthesis and characterization of ordered and disordered PdCu alloy electrocatalysts.
• Electrochemical testing of NO₃ RR performance, including selectivity, stability, and removal efficiency.
• In situ and ex situ X-ray absorption spectroscopy (XAS) to analyze catalyst structure and stability.

Main Results:

• Highly ordered PdCu electrocatalysts achieved 91% N₂ selectivity, 94% nitrate removal, and 480 h stability without catalyst loss.
• Disordered PdCu electrocatalysts showed poor selectivity (44% N₂, 49% NH₄⁺), instability, and significant copper loss.
• Structural ordering in PdCu alloys was found to enhance catalyst stability by preventing copper leaching.

Conclusions:

• Structural ordering is critical for designing stable and selective PdCu electrocatalysts for NO₃ RR.
• Ordered PdCu alloys offer a promising solution for mitigating nitrate pollution in water.
• Minimizing catalyst loss is essential for cost-effective and environmentally sound water treatment.