One-Step Syntheses of Face-Centered Cubic Os_xPt_1-x/C with Near-Zero-Overpotential Hydrogen Evolution from...

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Controlling solid solution catalyst structure and loading is crucial for catalytic performance but challenging with existing methods.
• Simultaneous control over loading states and crystal structure of catalysts remains an unmet need.

Purpose of the Study:

• To develop a novel synthetic approach for phase-controlled OsxPt1-x/C catalysts.
• To investigate the catalytic activity of these new catalysts for the hydrogen evolution reaction (HER).

Main Methods:

• A one-pot in situ polyol method was employed for catalyst synthesis.
• Phase-controlled synthesis of face-centered cubic (fcc)-dominated and well-dispersed immiscible OsxPt1-x/C was achieved.
• Electrochemical testing was performed to evaluate HER catalytic activities.

Main Results:

• The developed method successfully synthesized fcc-dominated OsxPt1-x/C catalysts.
• Most fcc-OsxPt1-x/C catalysts demonstrated enhanced HER activity compared to Pt/C.
• A record low overpotential of 1.0 mV at 10 mA·cm⁻² was achieved for fcc-Os0.3Pt0.7/C in 0.5 M H2SO4.

Conclusions:

• Osmium (Os) alloying in platinum (Pt) sites weakens hydrogen adsorption, optimizing reaction pathways for enhanced HER.
• The electronic state adjustments induced by Os alloying promote favorable H2 desorption.
• This work presents state-of-the-art HER catalytic activities, paving the way for efficient hydrogen production technologies.