3D-Porous Electrocatalyst with Tip-Enhanced Electric Field Effect Enables High-Performance Proton Exchange Membrane...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Inefficient mass transfer impedes the hydrogen evolution reaction (HER), a key process for green hydrogen production.
• Developing advanced catalytic systems is crucial to overcome these limitations.

Purpose of the Study:

• To design an efficient reactant-enriched system for enhanced mass transfer in HER.
• To integrate high-curvature platinum (Pt) nanocones with a 3D porous titanium aluminum (TiAl) framework.

Main Methods:

• Theoretical simulations and in situ spectroscopy (Raman, Fourier transform infrared) were used to analyze reactant concentration and electric fields.
• X-ray computed tomography and molecular dynamics simulations assessed ion diffusion in the 3D TiAl framework.
• Performance evaluation in a proton exchange membrane water electrolyzer.

Main Results:

• High-curvature Pt nanocones created a local electric field, increasing hydronium ion (H3O+) concentration by ~1.6 times.
• The 3D TiAl framework exhibited a hydronium ion diffusion coefficient over 16.7 times higher than commercial carbon supports.
• The Pt/TiAl-nanocone catalyst achieved high mass activity (17.2 mA cm-2 Pt) and an ultrahigh turnover frequency (TOF) of 42.9 s-1.
• In an electrolyzer, it reached 1.0 A cm-2 at 1.88 V and operated stably for 800 hours.

Conclusions:

• The integrated Pt/TiAl-nanocone system significantly enhances mass transfer and catalytic activity for HER.
• This approach offers a promising pathway for efficient and stable green hydrogen generation.