Compressive Strain in N-Doped Palladium/Amorphous-Cobalt (II) Interface Facilitates Alkaline Hydrogen Evolution

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Developing efficient catalysts for the alkaline hydrogen evolution reaction (HER) is crucial for renewable hydrogen energy systems.
• Palladium-based catalysts are promising but hindered by a strong palladium-hydrogen bond, limiting their performance in alkaline media.
• Existing catalysts often struggle to achieve high efficiency and stability under alkaline conditions.

Purpose of the Study:

• To overcome the limitations of palladium-based catalysts in alkaline HER.
• To design and synthesize a novel catalyst with enhanced activity and stability.
• To investigate the mechanism behind the improved catalytic performance.

Main Methods:

• Fabrication of a nitridation-induced compressively strained interface: N-doped palladium/amorphous cobalt (II) (N-Pd/A-Co(II)).
• Electrochemical characterization to evaluate HER activity and stability.
• Analysis of the catalyst's electronic structure and surface properties to understand the catalytic mechanism.

Main Results:

• The optimized N-Pd/A-Co(II) catalyst achieved an overpotential of only 58 mV at 10 mA cm⁻², significantly outperforming pure Pd and state-of-the-art Pt/C.
• The catalyst demonstrated excellent stability, with negligible performance decline over a 30-hour test.
• Compressive strain in N-doped Pd was found to reduce strong H_ads absorption, while amorphous Co(II) accelerated water dissociation.

Conclusions:

• The synergistic effect between compressively strained N-doped Pd and amorphous Co(II) creates highly efficient alkaline HER electrocatalysts.
• This study highlights the critical role of engineered interfaces in developing advanced catalysts for energy applications.
• The N-Pd/A-Co(II) catalyst represents a significant advancement for renewable hydrogen production.