Alternative Supports for Electrocatalysis of the Oxygen Evolution Reaction in Alkaline Media

At a Glance

Metadata	Details
Publication Date	2025-06-25
Journal	Electrochem
Authors	Gwénaëlle Kéranguéven, Ivan S. Filimonenkov, Thierry Dintzer, Matthieu Picher
Institutions	Technological Institute for Superhard and Novel Carbon Materials, Centre National de la Recherche Scientifique
Analysis	Full AI Review Included

Technical Documentation & Analysis: High-Stability Diamond Supports for OER Electrocatalysis

Executive Summary

This research validates Boron-Doped Diamond (BDD) as the superior support material for high-performance Oxygen Evolution Reaction (OER) electrocatalysts in alkaline media, directly addressing the critical durability challenges in Anion Exchange Membrane (AEM) electrolyzers.

Superior Stability: BDD demonstrated the highest anodic stability, exhibiting mass-normalized degradation currents 100 times lower (5 mA g^-1) than the benchmark Vulcan XC72 carbon (500 mA g^-1) at 1.58 V vs. RHE.
Application Focus: The study confirms BDD’s suitability as a robust anode support for Co₃O₄-based OER catalysts, crucial for improving the efficiency and lifetime of water electrolysis systems.
Methodological Rigor: The Rotating Ring-Disc Electrode (RRDE) technique was successfully employed to accurately separate true OER activity from parasitic support degradation currents, a necessity for reliable material benchmarking.
Durability Confirmed: BDD- and Fe₃O₄-based composites maintained high stability during 3-hour chronoamperometry tests at 1.66 V vs. RHE, whereas Vulcan XC72 and WC composites suffered significant degradation.
Performance Metrics: The BDD composite (16C0₃O₄ISACBDD) achieved a competitive mass-normalized OER activity of 14.2 A g^-1_oxide at 1.58 V vs. RHE.
6CCVD Value Proposition: 6CCVD specializes in the high-quality BDD materials required to replicate and scale this highly stable electrocatalyst platform for industrial and research applications.

Technical Specifications

The following hard data points were extracted from the analysis of support materials and the resulting Co₃O₄ composites.

Parameter	Value	Unit	Context
Electrolyte Medium	1 M NaOH	N/A	Alkaline OER environment
Anodic Potential Range	1.53 - 2.03	V vs. RHE	Potential steps used for stability testing
BDD Mass-Normalized Degradation Current (1.58 V RHE)	5	mA g^-1	Lowest degradation among all supports
Vulcan XC72 Mass-Normalized Degradation Current (1.58 V RHE)	500	mA g^-1	Highest degradation (100x BDD)
WC Mass-Normalized Degradation Current (1.58 V RHE)	65	mA g^-1	Intermediate stability
Fe₃O₄ Mass-Normalized Degradation Current (1.58 V RHE)	35	mA g^-1	Intermediate stability
BDD Specific Surface Area (S_BET)	181	m² g^-1	Nanostructured BDD powder characteristics
OER Activity (16C0₃O₄ISACBDD)	14.2 [12.6]	A g^-1_oxide	Mass-normalized activity at 1.58 V RHE
Tafel Slope (16C0₃O₄ISACBDD)	65	mV dec^-1	Measure of kinetic limitations
Stability Test Duration (High Potential)	3	hours	Chronoamperometry at 1.66 V vs. RHE
Co₃O₄ Nanoparticle Size (on BDD/Fe₃O₄/WC)	5-10	nm	Observed via TEM imaging

Key Methodologies

The experimental approach focused on rigorous synthesis and electrochemical characterization to ensure accurate measurement of OER activity and support degradation.

Composite Synthesis: Co₃O₄-based composites were prepared using the In Situ Autocombustion (ISAC) method, ensuring the active phase (Co₃O₄) nanoparticles (5-10 nm) were well-supported on the substrate surface.
Material Characterization: Comprehensive analysis utilized X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), and N₂-physisorption (BET/BJH methods) to define the structure, composition, and active surface area of the synthesized materials.
Electrochemical Setup: Electrocatalytic activity was evaluated using a thin-film approach on a Glassy Carbon (GC) disc in a Rotating Ring-Disc Electrode (RRDE) setup (1600 rpm) in 1 M NaOH electrolyte.
Degradation Separation: The RRDE method, using the ring electrode as an oxygen sensor, was crucial for discriminating the Oxygen Evolution Reaction (OER) current from the electrochemical support degradation currents (j_Disk (1-FE)).
Loading Control: Oxide loadings were strictly controlled (below 40 µg_oxide cm^-2) to ensure the measured current was proportional to the oxide loading and to prevent errors caused by vigorous oxygen bubble formation.
Durability Assessment: Stability was assessed using chronoamperometry at constant anodic potentials (1.66 V vs. RHE for 3 hours) to simulate relevant electrolysis conditions.

6CCVD Solutions & Capabilities

The research confirms that Boron-Doped Diamond (BDD) is the most stable platform for next-generation OER electrocatalysts, directly aligning with 6CCVD’s core expertise in MPCVD diamond materials. 6CCVD offers the high-quality, customizable BDD substrates necessary to scale this research from the lab to industrial AEM electrolyzer prototypes.

Applicable Materials for Replication and Scale-Up

To replicate and extend the high stability demonstrated in this paper, researchers require high-pquality BDD material. 6CCVD provides:

Heavy Boron Doped Polycrystalline Diamond (PCD BDD): Ideal for high-surface-area applications like the nanostructured powder used in this study. Our PCD BDD offers superior conductivity and electrochemical stability, essential for robust OER anodes.
Single Crystal Boron Doped Diamond (SCD BDD): Available for fundamental studies requiring ultra-low defect density and precise crystallographic orientation control, offering the ultimate in chemical inertness and electrochemical window width.
Custom Substrates: We provide BDD substrates (PCD and SCD) up to 10 mm thick and wafers up to 125 mm in diameter for large-format AEM anode development.

Customization Potential for Advanced OER Systems

The successful integration of BDD into commercial electrolyzers requires precise material engineering, a capability 6CCVD delivers:

Requirement from Research	6CCVD Customization Capability	Technical Advantage
High Stability Support	PCD BDD Wafers (up to 125 mm)	Enables scale-up from lab-scale RRDE discs to commercial-sized AEM anodes.
Surface Morphology Control	Precision Polishing (Ra < 5 nm for PCD)	Allows researchers to control the surface roughness and porosity, optimizing the nucleation and growth of Co₃O₄ nanoparticles during ISAC synthesis.
Electrode Integration	Custom Metalization (Ti, Pt, Au, W, Cu)	We offer in-house metalization services for direct integration of BDD substrates into flow cells, providing low-resistance contacts and eliminating the need for fragile thin-film coatings.
Thickness Optimization	SCD/PCD Thickness Control (0.1 µm - 500 µm)	Tailored thickness allows optimization of charge transport kinetics and mechanical robustness for specific electrolyzer designs.

Engineering Support

6CCVD’s in-house team of PhD material scientists and electrochemists can assist with material selection and optimization for similar Oxygen Evolution Reaction (OER) projects. We provide consultation on:

Optimizing boron doping levels for maximum conductivity and stability.
Selecting the ideal surface finish (polished vs. as-grown) for catalyst deposition methods (e.g., ISAC, electrodeposition).
Designing custom metal contacts for low-resistance current collection in high-current density applications.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The anodic stability of tungsten carbide (WC) and iron oxide with a spinel structure (Fe3O4) were compared against similar data for nanostructured, boron-doped diamond (BDD), and the benchmark Vulcan XC72 carbon, in view of their eventual application as alternative supports for the anion exchange membrane electrolyzer anode. To this end, metal oxide composites were prepared by the in situ autocombustion (ISAC) method, and the anodic behavior of materials (composites as well as supports alone) was investigated in 1 M NaOH electrolyte by the rotating ring-disc electrode method, which enables the separation oxygen evolution reaction and materials’ degradation currents. Among all supports, BDD has proven to be the most stable, while Vulcan XC72 is the least stable under the anodic polarization, with Fe3O4 and WC demonstrating intermediate behavior. The Co3O4-BDD, -Fe3O4, -WC, and -Vulcan composites prepared by the ISAC method were then tested as catalysts of the oxygen evolution reaction. The Co3O4-BDD and Co3O4-Fe3O4 composites appear to be competitive electrocatalysts for the OER in alkaline medium, showing activity comparable to the literature and higher support stability towards oxidation, either in cyclic voltammetry or chronoamperometry stability tests. On the contrary, WC- and Vulcan-based composites are prone to degradation.

Tech Support

Original Source

DOI: https://doi.org/10.3390/electrochem6030023

References

2023 - Highly mixed high-energy d-orbital states enhance oxygen evolution reactions in spinel catalysts [Crossref]
2020 - Boosting the electrochemical water splitting on Co3O4 through surface decoration of epitaxial S-doped CoO layers [Crossref]
2020 - Ultrafine Co3O4 nanolayer-shelled CoWP nanowire array: A bifunctional electrocatalyst for overall water splitting [Crossref]
2019 - Carbon materials as additives to the OER catalysts: RRDE study of carbon corrosion at high anodic potentials [Crossref]
2015 - Synthesis of efficient Vulcan-LaMnO3 perovskite nanocomposite for the oxygen reduction reaction [Crossref]
2020 - How key characteristics of carbon materials influence the ORR activity of LaMnO3- and Mn3O4-carbon composites prepared by in situ autocombustion method [Crossref]
2019 - Magnetic resonance study of lightly boron-doped diamond [Crossref]
2018 - Development of electrochemical applications of boron-doped diamond electrodes [Crossref]
2020 - Influence of temperature on the electrochemical window of boron doped diamond: A comparison of commercially available electrodes