Constructing Ru-Co₂P Lewis Acid-Base Pairs to Prompt Hydrogen Evolution Reaction in Alkaline Seawater Electrolyte

Area of Science:

• Electrochemistry
• Materials Science
• Green Chemistry

Background:

• Seawater electrolysis offers a sustainable route for green hydrogen generation.
• Challenges include slow water dissociation kinetics and chlorine-induced corrosion in alkaline environments.
• Developing robust electrocatalysts is crucial for industrial viability.

Purpose of the Study:

• To design and synthesize a novel electrocatalyst for efficient and stable alkaline seawater splitting.
• To investigate the synergistic effects of Lewis acid-base pair sites on catalytic performance.
• To elucidate the mechanism of water dissociation and hydrogen evolution.

Main Methods:

• Synthesis of Ru-Co2P decorated on nitrogen and phosphorus co-doped carbon (Ru-Co2P/NPC).
• Electrochemical characterization including hydrogen evolution reaction (HER) measurements in alkaline and seawater electrolytes.
• Density Functional Theory (DFT) calculations to understand reaction mechanisms and active sites.

Main Results:

• The optimized Ru-Co2P/NPC-2 catalyst achieved low overpotentials of 22.0 mV for 10 mA cm-2.
• Exceptional stability was demonstrated, operating steadily at 50 mA cm-2 for over 30 hours.
• Experimental and theoretical data confirmed the roles of Co (Lewis acid) and Ru-P (Lewis base) sites in optimizing water dissociation and hydrogen desorption.
• The catalyst exhibited enhanced anti-corrosion properties in the chloride-rich environment.

Conclusions:

• The rational design of dual Lewis acid-base sites on Ru-Co2P/NPC is highly effective for alkaline seawater electrolysis.
• This catalyst architecture significantly improves HER kinetics and stability while mitigating corrosion.
• The findings provide a promising pathway for developing efficient electrocatalysts for green hydrogen production from seawater.