Nanostructured Ir-supported on Ti4O7 as a cost-effective anode for proton exchange membrane (PEM) electrolyzers

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Proton exchange membrane (PEM) water electrolysis is crucial for large-scale hydrogen production from renewable energy.
• High cost of PEM electrolyzers is partly due to the significant amount of iridium (Ir) used in anodes.
• Developing cost-effective catalysts is essential for advancing this technology.

Purpose of the Study:

• To develop and characterize a novel, cost-effective catalyst for PEM water electrolysis.
• To reduce the reliance on expensive iridium-based materials in electrolyzer anodes.
• To enhance the efficiency and kinetics of the oxygen evolution reaction (OER).

Main Methods:

• Synthesis of iridium nanoparticles supported on titanium oxide (Ti4O7) via chemical reduction without thermal treatment.
• Characterization using electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM).
• Electrochemical evaluation through cyclic and linear voltammetry to assess OER performance.

Main Results:

• The synthesized Ir/Ti4O7 catalyst demonstrated uniform distribution of small iridium nanoparticles (approx. 1.8 nm) on the Ti4O7 support.
• XPS analysis indicated a metallic Ir to Ir-oxide ratio of 3:1.
• The Ir/Ti4O7 catalyst exhibited four times higher mass activity for OER compared to commercial Ir-black, with improved kinetics and turnover frequency.

Conclusions:

• The developed Ir/Ti4O7 catalyst offers a cost-effective alternative to traditional iridium anodes in PEM electrolyzers.
• This innovation can significantly reduce the precious metal loading required for efficient hydrogen production.
• The catalyst's superior performance in OER suggests its potential for widespread application in renewable hydrogen generation.