Atomic-Level Pt Electrocatalyst Synthesized via Iced Photochemical Method for Hydrogen Evolution Reaction with High...

Area of Science:

• Heterogeneous catalysis
• Electrocatalysis
• Materials science

Background:

• Metal particle morphology and size significantly impact catalytic activity.
• Controlling platinum (Pt) synthesis at the atomic level is crucial for understanding structure-activity relationships in electrocatalysis.

Purpose of the Study:

• To develop a strategy for synthesizing graphene-supported platinum electrocatalysts with controlled particle sizes (single atoms, nanoclusters, nanocrystals).
• To investigate the structure-activity relationship of these catalysts for the hydrogen evolution reaction (HER).

Main Methods:

• Iced photochemical method for synthesizing platinum nanocatalysts on graphene (Pt-SA@HG, Pt-Clu@HG, Pt-Nc@HG).
• Electrochemical measurements to evaluate HER performance.
• In situ X-ray absorption fine structure (XAFS) spectroscopy and density functional theory (DFT) calculations to identify active sites.

Main Results:

• Pt-SA@HG demonstrated exceptional HER performance with a low overpotential (13 mV at 10 mA cm⁻²), surpassing Pt-Clu@HG and Pt-Nc@HG.
• In situ XAFS and DFT calculations identified the Pt-C3 active site as key to the superior performance of Pt-SA@HG.
• The pure carbon-coordinated Pt-C3 site is more favorable for HER than traditional Pt-Nx structures.

Conclusions:

• The iced photochemical method provides a controllable route to synthesize graphene-supported platinum catalysts with tunable sizes.
• The Pt-C3 active site is identified as a highly efficient site for electrocatalytic HER.
• This work offers a novel approach for multiscale control of metal particle size and catalytic performance on graphene.