Metastable fcc-Ru/fcc-RuO₂ Heterointerphase for Hydrogen Evolution

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Metastable crystal structures offer unique properties but are challenging to synthesize.
• Ruthenium dioxide (RuO2) is a key material in catalysis, but its metastable forms are difficult to access.
• Developing efficient catalysts for water dissociation is critical for energy technologies.

Purpose of the Study:

• To develop a method for synthesizing metastable RuO2.
• To investigate the catalytic performance of heterophase Ru/RuO2 catalysts.
• To understand the relationship between crystal structure and catalytic activity.

Main Methods:

• Employing a moderate crystallographic transformation strategy.
• Controlling the degree of oxidation to create different heterophase Ru/RuO2 catalysts.
• Characterizing the catalysts' structure and electrochemical performance.

Main Results:

• Successfully synthesized metastable RuO2.
• Constructed heterophase Ru/RuO2 catalysts with varying oxidation states.
• Identified the metastable fcc-Ru/fcc-RuO2 heterointerphase as highly effective.
• Achieved a current density of 10 mA cm-2 at a low potential of 11.2 mV due to improved crystal matching, water dissociation, and intermediate adsorption.

Conclusions:

• A moderate crystallographic transformation is an effective strategy for synthesizing metastable RuO2.
• The metastable fcc-Ru/fcc-RuO2 heterointerphase demonstrates superior catalytic activity for water dissociation.
• This work offers a new approach for designing catalysts based on crystal phase engineering.