Generating Active Metal/Oxide Dynamic Interface through Triggering Hydroxyl Reverse Spillover for High-Performing...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Monitoring catalyst interfaces during reactions is crucial for efficient acidic oxygen evolution (OER).
• Achieving high performance and stability in OER catalysts under working conditions remains a challenge.

Purpose of the Study:

• To introduce a bias-induced activation strategy for IrO_x/SrTiO_3-x catalysts.
• To investigate the in situ modulation of catalyst leaching and hydroxyl reverse spillover for enhanced OER.

Main Methods:

• Operando X-ray absorption spectroscopy (XAS), differential electrochemical mass spectrometry (DEMS), and X-ray photoelectron spectroscopy (XPS).
• OH radical quenching experiments to confirm the reverse OH spillover mechanism.

Main Results:

• Bias-induced Sr leaching facilitates lattice oxygen-mediated hydroxyl radical formation and reverse spillover at the Ti-O-Ir interface.
• This mechanism bypasses conventional scaling relationships, enhancing catalytic efficiency and stability.
• The optimized catalyst achieved 3 A cm^-2 at 2.003 V and showed no decay over 800 h at 1 A cm^-2.

Conclusions:

• The reverse lattice oxygen spillover mechanism offers a novel pathway for designing efficient and durable OER catalysts.
• This strategy provides insights into surface redox chemistry beyond traditional OER design principles.
• The findings pave the way for advanced electrochemical energy conversion systems.