Regulating active hydrogen supply and intermediate binding for pH-universal H₂O₂ electrosynthesis at ampere-level...

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Chemistry

Background:

• Electrocatalytic oxygen reduction offers sustainable hydrogen peroxide (H₂O₂) production.
• Current methods face challenges like low efficiency, poor intermediate binding, and pH-dependent performance.
• Understanding catalyst modulation mechanisms is crucial for improvement.

Purpose of the Study:

• To develop an efficient, pH-universal electrocatalyst for H₂O₂ electrosynthesis.
• To investigate the mechanism of interfacial microenvironment modulation by functionalization.
• To demonstrate the practical application of the developed catalyst.

Main Methods:

• Sulfonic acid (SO₃H)-functionalization of carbon nanotubes (SCNT).
• Electrochemical experiments across a wide pH range (0.7-13).
• Theoretical calculations (e.g., DFT) to understand reaction mechanisms.
• Evaluation of H₂O₂ concentration, Faradaic efficiency, and current densities.
• Application testing for pollutant degradation and sterilization.

Main Results:

• SCNT enables efficient H₂O₂ electrosynthesis at ampere-level current densities (1.0-1.5 A cm⁻²).
• Achieved high Faradaic efficiencies (81.7-97.2%) and H₂O₂ concentrations (834-1537 mM) across diverse pH.
• SO₃H functionalization optimizes intermediate binding and desorption, enhancing reaction kinetics.
• Demonstrated cost-effectiveness (28.5% of anthraquinone process) and practical utility.

Conclusions:

• SCNT is a highly effective electrocatalyst for pH-universal H₂O₂ production.
• The study elucidates the mechanism of interfacial modulation for enhanced electrosynthesis.
• SCNT offers a sustainable and cost-effective alternative for H₂O₂ generation and application.