Pulsed-Current Operation Enhances H₂O₂ Production on a Boron-Doped Diamond Mesh Anode in a Zero-Gap PEM Electrolyzer

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Boron-doped diamond (BDD) electrodes offer unique electrochemical properties.
• Efficient anodic synthesis of hydrogen peroxide (H2O2) is crucial for various applications.
• Pulsed electrolysis parameters can significantly influence reaction efficiency and product selectivity.

Purpose of the Study:

• To investigate the anodic formation of H2O2 via water oxidation using BDD-coated niobium mesh electrodes.
• To evaluate the impact of pulsed electrolysis on H2O2 production and Faradaic efficiency.
• To determine optimal operating conditions for maximizing H2O2 concentration in a zero-gap electrolysis configuration.

Main Methods:

• Fabrication of BDD-coated niobium mesh electrodes via chemical vapor deposition.
• Electrochemical testing in a zero-gap cell configuration.
• Analysis of H2O2 concentration and Faradaic efficiency under varying pulsed electrolysis parameters (on-time, off-time, flow rate) and constant current electrolysis.

Main Results:

• A low electrolyte flow rate of 0.75 cm³ min⁻¹ was found to increase H2O2 concentration.
• An optimal pulsed electrolysis regime (2s on-time, 4s off-time) yielded the highest H2O2 concentration.
• Pulsed electrolysis increased H2O2 production by 70% compared to constant current electrolysis at 150 mA cm⁻².

Conclusions:

• Pulsed electrolysis is a promising strategy for enhancing H2O2 production efficiency using BDD electrodes.
• Optimizing pulse parameters and flow rate is critical for maximizing H2O2 yield in zero-gap electrolyzers.
• Further improvements may be achieved by tuning BDD morphology, flow dynamics, and electrolyte composition.