Inner Co Synergizing Outer Ru Supported on Carbon Nanotubes for Efficient pH-Universal Hydrogen Evolution Catalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient and cost-effective electrocatalysts is crucial for hydrogen production via electrochemical water splitting.
• The hydrogen evolution reaction (HER) is a key process in water splitting, requiring effective catalysts.

Purpose of the Study:

• To design and synthesize a novel, highly active, and durable multicomponent electrocatalyst for the hydrogen evolution reaction (HER).
• To investigate the synergistic effects between confined cobalt nanoparticles and ruthenium nanoparticles on carbon nanotubes for enhanced HER performance.

Main Methods:

• In-situ confinement of cobalt nanoparticles within bamboo-like carbon nanotubes (CNTs).
• Uniform deposition of ultralow loading ruthenium on the exterior walls of Co@CNTs (Co@CNTsǀRu).
• Atomic-scale structural investigations and theoretical calculations to understand catalytic mechanisms.
• Electrochemical performance testing in alkaline, acidic, and neutral media.

Main Results:

• The Co@CNTsǀRu catalyst demonstrated exceptional activity and durability for HER.
• Ultralow ruthenium loading (approx. 2.6 µg cm⁻²) was achieved.
• The catalyst required low overpotentials (10 mV in alkaline, 32 mV in acidic, 63 mV in neutral media) to reach a current density of 10 mA cm⁻².
• Synergistic electron coupling between Co and Ru optimized hydrogen intermediate adsorption and facilitated electron/mass transfer.

Conclusions:

• The Co@CNTsǀRu composite catalyst exhibits top-level catalytic activity for HER across various media.
• The rational design integrating confined metal nanoparticles with supported metal catalysts offers a promising strategy for developing advanced electrocatalysts.
• This work provides new insights into designing carbon-supported metal catalysts for practical hydrogen production applications.