Highly Stable and Efficient Oxygen Evolution Electrocatalyst Based on Co Oxides Decorated with Ultrafine Ru...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Efficient electrocatalysts are crucial for oxygen evolution reaction (OER) in anion exchange membrane (AEM) water electrolysis.
• Developing catalysts with high activity, durability, and cost-effectiveness remains a challenge.

Purpose of the Study:

• To synthesize and characterize novel hollow Co-based N-doped porous carbon spheres decorated with Ru nanoclusters (HS-RuCo/NC) as efficient OER electrocatalysts.
• To investigate the synergistic effects between RuO2 and Co3O4 in the heterostructure for enhanced OER performance and stability.
• To evaluate the performance of the developed catalyst in an AEM water electrolyzer.

Main Methods:

• Pyrolysis of carboxylate-terminated polystyrene-templated bimetallic zeolite imidazolate frameworks accommodating Ru (III) ions.
• Characterization of the hollow, porous structure and composition of the synthesized electrocatalysts.
• Electrochemical testing of the catalyst for OER activity and stability in alkaline media.
• Integration of the catalyst into an AEM water electrolyzer for device performance evaluation.

Main Results:

• The HS-RuCo/NC catalyst exhibits a unique hollow structure with hierarchical porosity, facilitating mass transport and exposing more active sites.
• Synergistic effects between in situ formed RuO2 and Co3O4 optimize the electronic configuration and reduce the energy barrier for OER.
• Co3O4 effectively suppresses RuO2 over-oxidation, leading to enhanced catalyst stability.
• The AEM water electrolyzer using HS-RuCo/NC achieved a cell voltage of 2.07 V at 1 A cm-2 and demonstrated excellent long-term stability, outperforming commercial RuO2-based electrolyzers.

Conclusions:

• The developed HS-RuCo/NC electrocatalyst demonstrates superior performance for OER in AEM water electrolysis.
• The hollow porous structure and synergistic RuO2-Co3O4 heterostructure are key factors for high activity and durability.
• This work provides a promising pathway for designing advanced electrocatalysts for efficient hydrogen production via water splitting.