MXene-Supported, Atomic-Layered Iridium Catalysts Created by Nanoparticle Re-Dispersion for Efficient Alkaline...

Area of Science:

• Materials Science
• Catalysis
• Electrochemistry

Background:

• Optimizing supported metal catalysts requires precise control over metal component structure and substrate interactions.
• Understanding catalytic configurations at the atomic scale (layers, clusters, single atoms) is crucial for enhancing performance.

Purpose of the Study:

• To synthesize and characterize an Iridium-on-MXene (Mo2TiCxTx) catalyst with tunable morphology.
• To investigate the catalytic activity of different Iridium nanostructures for the hydrogen evolution reaction (HER) under alkaline conditions.

Main Methods:

• Controlled synthesis of Iridium nanostructures on MXene substrates at elevated temperatures.
• Morphological characterization of the catalyst, transitioning from nanoparticles to atomic layers and single atoms.
• Electrochemical testing to evaluate HER activity in industry-compatible alkaline media.

Main Results:

• The catalyst exhibited a morphology transformation from nanoparticles to atomic layers and isolated single atoms on MXene nanosheets.
• The intermediate structure, predominantly Ir atomic layers, displayed the highest HER activity under alkaline conditions.
• Ir atomic layers showed superior HER activity compared to single atoms, indicating they are the primary active sites.

Conclusions:

• The study highlights the importance of structural design in developing highly efficient supported metal catalysts.
• A moderate interaction between Ir atomic layers and the MXene substrate, coupled with electron transfer, facilitates optimal H* adsorption for HER.
• Tailoring catalyst morphology, particularly to atomic layers, is a promising strategy for advancing electrocatalytic applications.