Energy-Efficient Electro-Fenton Oxidation Enabled by CoCu Dual-Atom Catalysts with High Oxygen Utilization

Area of Science:

• Advanced materials science
• Environmental chemistry
• Catalysis

Background:

• Recalcitrant organic pollutants pose significant environmental challenges.
• The Electro-Fenton (EF) process utilizes oxygen reduction reaction (ORR) for pollutant degradation.
• Existing EF catalysts struggle with distinct active sites for H2O2 synthesis and activation.

Purpose of the Study:

• To develop an integrated tandem ORR catalyst for enhanced oxygen capture and utilization.
• To improve the efficiency of H2O2 synthesis and its subsequent activation to hydroxyl radicals (•OH).
• To demonstrate the effectiveness of the novel catalyst in degrading bisphenol A (BPA) and assess its economic viability.

Main Methods:

• Fabrication of a CoCu diatomic pair catalyst with cyano modification (CoCu-DACs-CN).
• Electrochemical characterization and theoretical calculations (Density Functional Theory).
• Performance evaluation in an Electro-Fenton system for bisphenol A degradation and flow-cell testing.

Main Results:

• The CoCu-DACs-CN catalyst achieved an oxygen utilization efficiency (OUE) of 39.8%.
• 100% bisphenol A removal was achieved in 40 minutes with a rate constant of 0.57 min⁻¹.
• Theoretical calculations confirmed facilitated O2 adsorption and migration for efficient 2e⁻ ORR and •OH generation.
• A flow-cell device maintained 100% BPA removal without O2/air pumping.
• Technoeconomic analysis showed a 74.4% reduction in electrical energy consumption.

Conclusions:

• The integrated 2+1e⁻ tandem ORR catalyst (CoCu-DACs-CN) effectively addresses challenges in EF processes.
• The catalyst demonstrates high efficiency and stability for recalcitrant organic pollutant removal.
• The developed EF process offers a promising, energy-efficient solution for wastewater treatment.