High-Period Element Doping as a Key Driver of Hydrogen Evolution in a Proton Exchange Membrane Water Electrolyzer

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Proton exchange membrane water electrolysis (PEMWE) is crucial for sustainable hydrogen production.
• Catalyst cost and stability in acidic conditions are major limitations for PEMWE.
• Developing efficient and durable electrocatalysts is essential for advancing PEMWE technology.

Purpose of the Study:

• To develop novel electrocatalyst supports using group VA element-doped graphitic nanoplatelets (XGnPs).
• To enhance the activity and durability of platinum-based catalysts for PEMWE.
• To investigate the effect of heteroatom doping on catalyst performance and hydrogen evolution reaction (HER) kinetics.

Main Methods:

• Synthesis of group VA element-doped graphitic nanoplatelets (XGnPs).
• Preparation of platinum nanoparticles on XGnPs (Pt@XGnPs) electrocatalysts.
• Electrochemical characterization including overpotential and Tafel slope measurements.
• System-level testing of PEMWE devices.
• Density functional theory (DFT) calculations to understand reaction mechanisms.

Main Results:

• Pt@XGnPs catalysts demonstrated improved charge transfer and metal-support interactions.
• Pt@SbGnP exhibited superior performance with a low overpotential (15.3 mV at 10 mA cm⁻²) and Tafel slope (27.8 mV dec⁻¹), outperforming commercial Pt/C.
• System-level tests showed high current densities and Faradaic efficiency.
• DFT calculations confirmed that heteroatom doping optimizes charge transfer for efficient HER kinetics.

Conclusions:

• Group VA element-doped graphitic nanoplatelets are effective supports for enhancing PEMWE electrocatalysts.
• The Pt@SbGnP catalyst offers a promising pathway for cost-effective and stable hydrogen production via PEMWE.
• Heteroatom doping is a viable strategy to tune electronic properties and boost catalytic activity for the hydrogen evolution reaction.