Proton Donors Boost Interfacial Water Activation on RuO₂-Embedded RuWO_x for Durable Acidic Oxygen Evolution

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• The acidic oxygen evolution reaction (OER) faces an activity-stability dilemma due to conflicting interfacial requirements for water enrichment and proton transfer.
• Existing catalysts struggle to simultaneously enhance interfacial water accumulation and deprotonation kinetics, hindering efficient OER performance.

Purpose of the Study:

• To design a novel electrocatalyst that overcomes the activity-stability dilemma in acidic OER.
• To achieve simultaneous enhancement of interfacial water enrichment and proton transfer kinetics for improved OER performance and stability.

Main Methods:

• Design and synthesis of a tungsten-stabilized ruthenium oxide heterostructure (RuWOₓ-300).
• Characterization using electrochemical measurements (overpotential, current density, stability tests).
• Computational simulations (ab initio molecular dynamics - AIMD) and in situ spectroscopy (Raman) to elucidate the catalytic mechanism.

Main Results:

• RuWOₓ-300 exhibits exceptional OER activity with low overpotentials (179 mV at 10 mA cm⁻², 231 mV at 100 mA cm⁻²).
• The catalyst demonstrates remarkable long-term stability (>4820 h at 50 mA cm⁻²), outperforming commercial RuO₂.
• W⁶⁺ species enhance water enrichment via localized electrostatic fields, while W-O-Ru sites act as Brønsted acid sites for accelerated deprotonation.

Conclusions:

• The RuWOₓ-300 heterostructure effectively resolves the activity-stability dilemma in acidic OER.
• A dual-functional mechanism involving proton-donor-mediated interfacial water activation enhances OER performance and suppresses catalyst dissolution.
• This work presents a new design strategy for highly active and stable acidic OER electrocatalysts.