Multimetal Doping and Heterostructure Engineering of RuO₂ for Durable and Efficient Oxygen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The oxygen evolution reaction (OER) is a critical bottleneck in water electrolysis, demanding highly efficient and stable catalysts.
• Current catalysts like RuO2 and IrO2 face limitations in terms of cost, durability, and efficiency, particularly under demanding conditions.

Purpose of the Study:

• To develop a novel, highly active, and durable catalyst for the oxygen evolution reaction (OER).
• To investigate the structure-property relationships of a multimetal-doped heterostructured oxide catalyst.
• To establish a new strategy for designing advanced OER catalysts using heterointerface engineering.

Main Methods:

• Synthesis of a MnCoNi-RuO2 (MCN-RuO2) heterostructured catalyst using impregnation-annealing-etching.
• Comprehensive structural characterization including X-ray diffraction and electron microscopy.
• Electrochemical performance evaluation in acidic media and within an anion exchange membrane water electrolyzer.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms and electronic properties.

Main Results:

• The MCN-RuO2 catalyst exhibited excellent OER activity with a low overpotential of 200 mV at 10 mA cm−2 and a low Tafel slope.
• The heterostructure demonstrated superior stability compared to commercial RuO2 and IrO2, maintaining high activity for 100 hours in an electrolyzer.
• DFT calculations confirmed that multimetal doping and defect engineering reduce activation energy for the rate-determining step and enhance catalyst stability.

Conclusions:

• The developed MCN-RuO2 catalyst represents a highly efficient and stable alternative for the oxygen evolution reaction, crucial for water electrolysis.
• Heterointerface engineering and multimetal doping are effective strategies for designing advanced, iridium-free OER catalysts.
• This work provides a promising platform for next-generation electrocatalysts for clean energy applications.